This question is supposed to be solved soon.

6. He is known to be preparing for his exams.

Model I: It is known that he will make his report ^: today. ■

He is known to make his report today.

1. It is believed that the method involved is good. 2. It is expected that they will take part in this research work/ •

3. It is known that evaporation goes more rapidly at the higher temperature. 4. It was known even in ancient times that water is denser than air.

Model II: It was found that those rays had been de­flected.

Those rays were found to have been de- fleeted.

1. It was known that the substance had been purified. :

2. It was considered that the method had been improved. :

3. It was known that the investigations carried out by him had resulted in new discoveries. 4. It is believed that they have examined this substance sufficiently.

Ex. 4. Combine the sentences using the Subjective Infinitive Con­struction as in the model:

Model: He has graduated from the Institute. I know it.

He is known to have graduated from the In­stitute.

1. M. Curie discovered radium. Everybody knows that.

2. He has finished his work. They said to us about it. 3. They work in the laboratory of organic chemistry. We know that.

4. The meeting will take place in our club. Wa were informed about it. 5. She has passed all her exams well. I know it.

Ex. 5. Compare the following pairs of sentences, translate them into Russian:

1. The science of chemistry is known to deal with sub­stances.

We know the science of chemistry to deal with sub­stances.

2. Every crystal has been found to consist of atoms arranged in a three-dimensional pattern.

They have found every crystal to consist of atoms ar­ranged in a three-dimensional pattern.

3. Wilhelm Konrad Rontgen is known to have discovered a new kind of rays which he called X-rays.

Everybody knows Wilhelm Konrad Rontgen to have discovered a new kind of rays which he called X-rays.

4. Helium atom was stated to contain two electrons both of which are held tightly.

The scientists stated helium atom to contain two elec­trons both of which are held tightly.

5. The substance concerned is supposed to have been prepared by the reaction of some metals with water.

The scientists suppose this substance to have been prepared by the reaction of some metals with water.

Ex. 6. Remember the words which have the same form as nouns and verbs, translate them into Russian;

present v, n measure v, n range v, n use v, n

flow v, n form v, n

amount v, ti

Notes on the Text

1. one part per million — одна часть на миллион

2. on a substantial scale — в больших масштабах

3. to amount to — составлять; равняться (чему-л.); достигать (чего-л.)

Mercury is known to be a rare element. The element is found in trace amounts throughout the lithosphere (rocks and soil), the hydrosphere, the atmosphere and the biosphere (in tissues of plants and animals).

In the rocks and soil mercury is found to be measured in fractions of one part per million.

In the hydrosphere (the seas and fresh waters) it occurs only in parts per billion. In the atmosphere mercury is pres­ent both as vapour and in the form of particles.

It should be noted, however, that under natural condi­tions the amount of mercury in the atmosphere is so small that extremely sensitive methods are required for detecting and measuring it.

The situation is somewhat different in the biosphere. Plants and animals tend to concentrate mercury. For exam­ple, it has been found some marine algae to contain a con­centration of mercury more than 100 times higher than that in the seawater in which they live.

Mercury today is used on a substantial scale in chemical industries, it being used in the manufacture of paints and paper as well as in agriculture. The world production of mercury has been found to amount to about 10,000 tons per year.

In agriculture mercury in the form of corrosive subli­mate (HgCl₂) can be used for disinfecting seeds. The chlo­rides of mercury are employed in protecting a number of vegetable crops.

Due to such large-scale uses a considerable amount of mercury waste is likely to flow into the air, the soil, the streams, rivers, lakes. One might ask whether all these may present a threat to health?

In order to answer this question it is necessary to exam­ine the forms in which mercury occurs. Liquid mercury itself is not toxic to man, but mercury vapour, however, can be injurious.

The soluble inorganic salts of mercury have long been known to be toxic.

So, knowing properties and forms of mercury it is possible to use it.

Mercury being very important, it is useful to continue investigating its properties very closely.

always do everything in due time. 14. Do you know that a quite new property of this substance was observed? 15. 141 do my best to study well.

Ex. 12. Translate the following constructions into Russian:

1. Having examined the substance, they . . .

2. They having investigated the substance, the analyst

3. His investigating these phenomena resulted in . . .

4. The scientists having done new discoveries, it was . . .

5. The examination of this mixture being carried out, they . . .

Ex. 13. State the functions of the Infinitives and translate the following sentences into Russian:

1. At least three of the remaining four particles are needed to account for the observed relationships. 2. This substance was purified to investigate its properties carefully. 3. Lead is known to be a bright silvery metal with a pronounced bluish colour. 4. The radiation was first thought to consist of gamma-rays, but the energy relationships were found to disagree with this assumption. 5. They proved soluble lead salts to be poisonous. 6. They have been told to ex­amine all the found precipitates. 7. The laboratory appeared to have been equipped very well. 8. The sediment to be investigated appeared on the bottom of the flask. 9. They are likely to have proved this solvent to be very volatile.

8. They were asked to find out all the constituents of the compound. 11. A series of experiments was conducted to determine the effect of adding this element.

Ex. 14. Analyse the“ing”-forms and translate the sentences into Russian:

1. Copper being a good electrical conductor, they used it in their experiment. 2. Like all soluble aluminium salts, the sulphate is readily hydrolyzed, yielding both aluminium “hydroxide” and a solution which is acidic. 3. As a result of one reaction decreasing in velocity while the other is increasing, a point presently is reached at which the two reactions are proceeding at the same rate and the products of each reaction are being used up at the same rate at which they are formed. 4. The temperature increased, the heat being evolved. 5. The solution obtained, we could begin carrying out our experiment. 6. A steel containing some metallic element other than iron and carbon is generally known as “special steel”. 7. Large amounts of hydrogen are

used in industry in converting oils into solid fats. 8. Many nuclear reactions result from interacting of nuclei and neu­trons. 9. Using only very small quantities of the substances he succeeded in obtaining a considerable amount of infor­mation about the chemical properties of the elements. 10. Mer­cury may be purified by washing it with dilute nitric acid.

8. They were using this substance in their experiment sev­eral times. 12. While examining the properties of this metal pay attention to its melting point. 13. Upon ЬетГ) heated the oxide changes into the red modification. 14. Being lower than hydrogen in the activity, mercury does not dis­place hydrogen from solutions of the acids. 15. His having created this new machine soon became known to everybody. 16. All nitrates decompose upon being heated and hence serve well as dry oxidizing agents.

■ \

Ex. 15. Translate the text and render it:

Mercuric oxide is obtained as a bright, orange-red, crys­talline substance either by heating mercury in air or by the pyrolysis of mercuric nitrate.

It is also obtained as a yellow precipitate when soluble, basic hydroxides are added to solutions of mercuric nitrate, the hydroxide undergoing spontaneous decomposition.

The yellow oxide is known to differ from the red only in that its particles are of smaller size.

Upon being heated it changes into the red modification. The other mercuric salts are usually prepared by treating either the oxide or free mercury with the appropriate acid.

Ex. 16. Translate the text:

Metallic mercury can be obtained by heating the sul­phide ore in air with sulphur dioxide as a by-product;

HgS + 0₂-+Hg + S0₂

Mercury vapour is condensed from the gaseous products. Mercury may be purified by washing it with dilute nitric acid, which oxidizes the more active metallic impurities present, especially zinc and cadmium.

Hot mercury vapour is known to conduct electricity and give out light that is rich in the ultraviolet rays.

The common metals except iron and platinum form al­loys with mercury, known as amalgams.

Mercury is unusual in that it is the only metal which is stable in the liquid state at about 20°C. It has a bright silvery luster, shows little tendency to tarnish at ordinary temperature, it being a good conductor of both heat and electricity.

Because of its uniform expansion over a wide range of temperature, it is well adapted to use in thermometers/ and due to its high density, low coefficient of expansion, and slight vapour, pressure at ordinary temperature it is well suited for using in the liquid type barometer.

Despite having high boiling point, mercury does show a small vapour pressure even at ordinary temperatures.

Being raised to a temperature above its boiling point, mercury vapour readily conducts electricity at the same time emitting radiation, it being rich in ultraviolet rays.

rock

tissue

plant

soil

however to tend substantial

Ex. 7. Answer the following questions:

1. Where can mercury be found? 2. What methods are required to detect the presence of mercury in the atmosphere?

3. Where is mercury used? 4. In what form is mercury used in agriculture? 5. What is mercury used for in agriculture?

6. Why is mercury considered to be unusual metal? 7. What properties of mercury do you know? 8. Why can mercury be used in thermometers and barometers? 9. When does mer~ cury conduct electricity?

Ex. 8. Retell the text according to the following plan:

1. The occurrence of mercury.

2. The use of mercury.

3. The importance of mercury.

4.. Properties of mercury.

Ex. 9. Translate the following sentences paying attention to the words in bold type;

1. By close study they could learn that the vapours of this substance are dangerous. 2. The similarity of mercury to zinc and cadmium is not very close, the metal showing a greater similarity to copper and silver. 3. Close the test tube until the solution cools. 4. The elements of Group II-B and IV-B of the Periodic System closely resemble the ele­ments of Group III and IV respectively. 5. One degree is the one hundredth part of the temperature range between the normal freezing and boiling points of water. 6. The ⁶Li Content of samples encountered in this laboratory has ranged from 4 to 98%. 7. The amount of water was not enough to carry out this experiment. 8. It should be noted that the increase in temperature amounted to only 20°C.

Ex. 10. Choose the Russian equivalents from the right column:

due to considerable somewhat present to be present to be due to in order to to amount to ordinary

Ех. 11. Explain the meaning of the verb “to do” in the following sentences:

1. The old methods of carrying out such experiments should be done away with. 2. What do you usually do in the laboratory? 3. He will do his best to finish his work in time. 4. Among the gases with which mercury does react is hydrogen sulphide. 5. Being lower than hydrogen in the activity series mercury does not displace hydrogen from solution but it does react with the oxidizing oxides to form their respective salts. 6. The substance does support com­bustion. 7. While no exchange takes place between chlo­ride bromate and the corresponding halogen in neutral so­lutions exchange does occur if the solution is acidified. 8. Gold does not combine with oxygen or with sulphur and does not react with any familiar acids. It does, however, combine with chlorine and bromine. 9. Copper does not displace hydrogen from acids, but does react with acidic oxidizing agents. 10. They did carry out this work in due time. 11. Des­pite its high boiling point, mercury does show a small vapour fflfessure even at ordinary temperature. 12. They did their flpftie task very well though it was rather difficult. 13. They

2. always do everything in due time. 14. Do you know that a quite new property of this substance was observed? 15. I’ll do my best to study well.

Ex, 12, Translate the following constructions into Russian:

1. Having examined the substance, they . . .

2. They having investigated the substance, the analyst

3. His investigating these phenomena resulted in . . .

4. The scientists having done new discoveries, it was . . .

5. The examination of this mixture being carried out, they . . .

Ex. 13. State the functions of the Infinitives and translate the following sentences into Russian:

1. At least three of the remaining four particles are needed to account for the observed relationships. 2. This substance was purified to investigate its properties carefully. 3. Lead is known to be a bright silvery metal with a pronounced bluish colour. 4. The radiation was first thought to consist of gamma-rays, but the energy relationships were found to disagree with this assumption. 5. They proved soluble lead salts to be poisonous. 6. They have been told to ex­amine all the found precipitates. 7. The laboratory appeared to have been equipped very well. 8. The sediment to be investigated appeared on the bottom of the flask. 9. They are likely to have proved this solvent to be very volatile.

10. They were asked to find out all the constituents of the compound. 11. A series of experiments was conducted to determine the effect of adding this element.

Ex. 14. Analyse the “ing”-forms and translate the sentences into Russian:

1. Copper being a good electrical conductor, they used it in their experiment. 2. Like all soluble aluminium salts, the sulphate is readily hydrolyzed, yielding both aluminium “hydroxide” and a solution which is acidic. 3. As a result of one reaction decreasing in velocity while the other is increasing, a point presently is reached at which the two reactions are proceeding at the same rate and the products of each reaction are being used up at the same rate at which they are formed. 4. The temperature increased, the heat being evolved. 5. The solution obtained, we could begin carrying out our experiment. 6. A steel containing some metallic element other than iron and carbon is generally known as “special steel”. 7. Large amounts of hydrogen are

used in industry in converting oils into solid fats. 8. Many nuclear reactions result from interacting of nuclei and neu­trons. 9. Using only very small quantities of the substances he succeeded in obtaining a considerable amount of infor­mation about the chemical properties of the elements. 10. Mer­cury may be purified by washing it with dilute nitric acid.

10. They were using this substance in their experiment sev­eral times. 12. While examining the properties of this metal pay attention to its melting point. 13. Upon bein$ heated the oxide changes into the red modification. 14. Being lower than hydrogen in the activity, mercury does not dis­place hydrogen from solutions of the acids. 15. His having created this new machine soon became known to everybody. 16. All nitrates decompose upon being heated and hence serve well as dry oxidizing agents.

' \

Ex. 15. Translate the text and render it:

Mercuric oxide is obtained as a bright, orange-red, crys­talline substance either by heating mercury in air or by the pyrolysis of mercuric nitrate.

It is also obtained as a yellow precipitate when soluble, basic hydroxides are added to solutions of mercuric nitrate, the hydroxide undergoing spontaneous decomposition.

The yellow oxide is known to differ from the red only in that its particles are of smaller size.

Upon being heated it changes into the red modification. The other mercuric salts are usually prepared by treating either the oxide or free mercury with the appropriate acid. -

Ex. 16. Translate the text:

Metallic mercury can be obtained by heating the sul­phide ore in air with sulphur dioxide as a by-product:

HgS + 0₂-,Hg + S0_a

Mercury vapour is condensed from the gaseous products. Mercury may be purified by washing it with dilute nitric acid, which oxidizes the more active metallic impurities present, especially zinc and cadmium.

Hot mercury vapour is known to conduct electricity and give out light that is rich in the ultraviolet rays.

The common metals except iron and platinum form al­loys with mercury, known as amalgams.

Grammar; I. The Subjective Infinitive Construction (continua­tion).

2. Review of that, those,

Ex. 1. Pronounce the following words:

Ex. 2. Read the following word combinations fluently:

nuclear fission; unstable nuclei; in attempting to pre­pare; slow-moving neutrons; nearly equal; direct calori­metric measurement; two-gram atoms; two and a half mil­lion times; spontaneous fission; intermediate mass; one millionth of a second.

Study and remember the following charts:

1. 

   № 1

   № 2

   № 3

   He proves to work at this problem.

2. They seemed to be interested in this work.

3. She appeared to deal with this branch of chemistry.

4. He happened to be in Moscow.

5. This turned out to be very simple.

1. They proved to have examined this substance.

2. He appeared to have attended the lecture,

3. She seemed to have completed her tests.

4. He happened to have taken part in the dis­cussion.

1. He is likely to be in the laboratory.

2. She is unlikely to know him.

Ex. 3. Compare the following pairs of sentences, and translate them into

Russian:

1. The article appeared in our magazine yesterday.

The article appeared to be very interesting.

2. He proved this phenomenon tentatively.

He proved to know this law.

Ex. 4. Paraphrase the following sentences using the Subjective Infinitive Construction:

1. It seems that they have already purified the substance.

2. It appears that the iron rod has been rusted. 3. It happened that the method had been unsuitable. 4. It happened that he had discovered some new and very interesting properties of this element. 5. It seemed that the temperature had been raised. 6. It is likely that they have translated the article.

7. It appears that he has passed all his exams very well.

8. It happened that they had carried on their research si­multaneously. 9. It seemed that this solution was more con­centrated.

Ex. 5. Find the sentences with the Subjective Infinitive Construction. Translate the sentences into Russian:

1. The new method appeared to be very tedious and time- consuming. 2. The atoms of unconfined elements proved to be electrically neutral. 3. Elements composed of atoms containing only one or two valence electrons prove to form positive ions by giving up electrons during their reactions.

4. This new element has been discovered to be very useful.

5. They knew this new element to have been discovered and used. 6. The concentration of the solute particles seems to be less than an integral multiple of the molecular concen­tration. 7. The question known to be very important will be discussed very soon. 8. Many of the substances determined to be soluble will be carefully investigated. 9. Zinc and cadmium are used widely to protect iron and steel from rust.

10. The concentration of chromate ions required to establish this condition may be secured through the use of a weakly acidic solution of potassium chromate. 11. During the burn­ing of coal there appears to be a loss of weight. 12. No single set of properties is sufficient to serve for the definition of matter. 13. The changes reported to take place are shown in this table. 14. These changes were found to follow certain rules. 15. The particles shown to be negatively charged were used in this device. 16. The Beta rays were shown to be negative particles. 17. The element helium is known to

have been discovered in the sun. 18. Organic chemistry is known to be defined as the chemistry of compounds contain­ing carbon. 19. The experimentor knew this substance to be absolutely pure. 20. The procedure to be used for this work must be very accurate.

Ex. 6. Find the sentences in which “that”, “those” substitute nouns:

1. Before this discovery, it had been supposed that spe­cific composition and formula could represent only one substance. 2. The density of ice proved to be lower than that of the liquid. 3. The volume of steam has been found to be many times that of liquid water. 4. The energy lib­erated by the complete disintegration of lg of radium into lead is equivalent to that obtained by the combustion of more than half a ton of coal. 5. The range is greater for atoms of even atomic numbers than for those of odd numbers.

6. This review reveals that all atomic nuclei are believed to contain protons. 7. The neutron cannot be accelerated by use of the electric machine, but slow-moving ones appear to be more effective than are those of greater speed. 8. Ger­manium resembles silicon in that it forms several unstable hydrides. 9. Vessels made of platinum-rhodium alloy are even less susceptible to loss of weight on heating than are those made of platinum alone. 10. They had to use those vessels which were less susceptible to loss of weight on heat­ing. 11. We make use of the heat energy that is evolved when wood and coal change into gases and ashes to heat our homes and to provide power for industry. 12. Chemical research today is proceeding more rapidly than that before. 13. These are a number of substances that absorb moisture.

Notes on the Text

1. Not at all — вообще не, совсем не text. Nuclear fission

Nuclear fission is known to be a new type of transmutation, it being discovered as a result of attempts to prepare iso­topes of elements of atomic number greater than 92.

It should be noted that unstable nuclei ordinarily disin­tegrate into particles of disparate mass and charge. In these cases the larger particle is usually an atom whose mass dif­fers not at all, or only by a few units from that of the parent atom.

When in attempting to prepare atoms of an atomic num­ber higher than that of uranium, that element was bombarded with slow-moving neutrons, it was found that some of its atoms were split into two particles, their mass and charge being nearly equal.

Disintegration of this type was named nuclear fission, and was found to be accompanied by the evolution of tre­mendous quantity of energy.

It was verified by the direct calorimetric measurement that a very large amount of energy is liberated by fission, over 5xl0¹² calories per mole. Since a pound of uranium contains about 2 gram-atoms, the complete fission of one pound of this element, or a similar heavy element, produces about lOxlO¹² calories. This may be compared with the heat of combustion of 1 pound of coal, which is approxi­mately 4X10⁶ calories. Thus uranium as a source of energy may be 2.5 million times more valuable than coal.

Uranium 235 and plutonium 239, which can be made from uranium 238, are found to be capable of undergoing fission when exposed to slow neutrons.

It was shown that the thorium isotope ²³²Th undergoes fission under the influence of fast neutrons. It seemed like­ly that all of the elements with atomic number 90 or great­er can be made to undergo this reaction.

Uranium and thorium are considered to be important sources of heat and energy in the world.

The fission reactions can be chain reactions. These re­actions prove to be initiated by neutrons. A nucleus ²⁸⁶U, for example, may combine with a neutron to form ²³⁶U. This isotope happens to be unstable, and to undergo spontaneous fission, into two particles of roughly equal atomic number, the sum of the atomic numbers being 92, that is, the protons in the ²³⁶U nucleus are divided between the two daughter nuclei.

These daughter nuclei appeared to contain some of the neutrons originally present in the ²³⁸U nucleus. Since, how­ever, the ratio of neutrons to protons is greater in the heav­ier nuclei than in those of intermediate mass, the fission is also accompanied by the liberation of several free neutrons. The neutrons which are thus liberated may then combine with other ²³⁶U nuclei, forming additional ²³⁶U nuclei which themselves undergo fission. A reaction of this sort, the prod­ucts of which cause the reaction to continue, is called a chain reaction.

If a few pounds of or ^??0Pu are brought together sud-

^gnly (within about one millionth of a second) into a small yotpme, the chain fission of the nuclei occurs nearly com­pletely, and an amount of energy is released equal to that accompanying the detonation of about twenty thousand tons of a high explosive.

The foregoing text illustrates the great significance of nuclear fission and fissionable elements as a source of Energy. Taking into account that uranium and thorium are hot rare elements, but are among the more common elements, can understand the promise of nuclear energy for the tyorld of the future, and the possibility of its contributions to human welfare.

6X« t. Remember the following words:

fission nuclei disparate to split tremendous to verify pound to initiate

Bk. 8. Answer the following questions;

1. What is nuclear fission? 2. How was nuclear fission discovered? 3. What nuclei ordinarily disintegrate into particles of disparate mass and charge? 4. What is the larg- ёГ particle in these cases? 5. What element was bombarded

!^rith slow-moving neutrons? 6. What was found when ura- ium was bombarded with slow-moving particles? 7. What 'as named nuclear fission? 8. What was verified by direct calorimetric measurement? 9. How many calories can be produced by the complete fission of one pound of uranium?

10. What elements are capable of undergoing fission when ^kposed to slow neutrons? 11. What elements are considered tp be important sources of heat and energy in the world?

12. What reactions are initiated by neutrons?

Ex. 9. Retell the text according to the following plan:

1. Definition of nuclear fission.

2. Unstable nuclei.

8. The results obtained in attempting to prepare atoms of an atomic number higher than that of uranium.

4. Uranium is a source of energy.

5. Chain reactions.

6. The importance of nuclear fission.

Ex. Ю. Answer the questions as in the model. (Work in pairs.)

Model: Nuclear fission is a new type of transmutation.¹

Isn't it?

Yes, it is. No, it is not.

1. Disintegration of this type is named nuclear fission, Isn’t it? 2. He obtained good results. Didn’t he? 3, It is a new method, isn’t it?

Ex. 11. Translate the following sentences into Russian paying attention ¹ to the words in bold type;

1. Changes involving identical materials prove to pro­duce the same results. 2. The results of our investigation are surely to be correct. 3. This new element is known to have been discovered as a result of great experimental ac­tivity. 4. No solution will result from mixing two immis­cible liquids. 5. It is now believed that complex ions result from the sharing of electron pairs by the simple ion and the ions or molecules which become attached to it. 6. Great results in different fields of science have been achieved re­cently. 7. Disintegration will continue through a number of expulsions until a stable nucleus results. ' ^:

Ex. 12. Translate the following text, mind the Infinitives:

All of the simple particles which exist in nature have., been found to undergo reactions in which they prove to be,' converted into or obtained from other particles or radiation,,. There are no particles which are immutable and which can' be said to be truly fundamental. "

These particles can be considered to serve as the building . units for more complicated forms of matter. Thus the deu- teron, the nucleus of ²H, can be considered to be built up from / a proton and a neutron.

Ex. 13. Open the brackets choosing the suitable word and translate the sentences into Russian:

1. The capture of neutrons by the atoms of uranium, tho­rium and protactinium is known (to result from, to result in) forming of heavier isotopes. 2. I can’t start working (till, until) he comes, as he has got all the necessary figures. 3. (On­ly, the only) chemicals examined in our laboratory should be used in our work. 4. The only method available for this work (till, until) recently was the gravimetric method.

8, Having carried out a number of investigations, Fermi succeeded in creating the (natural, artificial) isotope. 6. Since the atomic nuclei of radioactive elements differ from (that, those) of nonradioactive elements only in the number of

frotons and electrons which they contain, it is believed hat radioactivity (results in, results from) instability of pertain atomic nuclei. 7. Ammonium salts greatly resemble (those, that) of the alkali metals especially (that, those) of

fotassium. 8. The positively charged particles are known о be called alpha-rays, (those, that) negatively charged are called beta-rays. 9. The ordinary heterogeneous reaction is (that, those) involving solid catalysts with liquid or gas­eous reactants. 10. The properties of the oxide of deuterium are similar to (those, that) of water but still there are small differences.

Ex. 14. Find the line in which there are only nouns:

1. fission, unstable, charge, transmutation;

2. violent, speed, instability, fragment, range;

3. pair, cause, fission, intermediate, emission;

4. release, subject, decrease, excess, stability.

Ex. 15. State the meaning of the word “cause" in the following sentences:

1. Heat to be absorbed by a liquid causes the liquid to evaporate. 2. Pressure in any fluid is due to one of two causes either compression or the weight of the fluid itself. 3. Since liquid water occupies a smaller volume than its solid, mod­erate pressure tends to cause ice to melt. 4. The difference between the voltage actually required to cause a reaction to proceed and the theoretical voltage calculated for the process is known as overvoltage. 5. The cause of his giving up this interesting work was unclear. 6. Combustion is caused by union of the oxygen atoms of the air with the carbon and hydrogen atoms of the fuel. 7. Moving through air causes air resistance. 8. All sources of sound cause the air to vibrate in different ways. 9. A. L. Lavoisier's explanation of com­bustion phenomena caused a revolution in chemistry. 10. Pres­sure changes caused by differences between the external and the internal vapour pressure may have more serious conse­quences.

Ex. 16. Read the text and give a summary of it:

As has already been said, the discovery made before has opened up a new source of projectiles in the form of neutron.

Therefore E. Fermi was sure that he could use neutrons to produce nuclei whose masses exceed the mass of uranium, i.e. transuranic elements. These nuclei were expected not to be stable, but radioactive.

Their position in the periodic system of elements could only be determined on the basis of half-life and the disin­tegration products.

During the study of such experiments, Otto Hahn found nuclei whose position could be in the centre of the periodic table. He realised that it was not a matter of constructing a new nucleus but of a fission of the bombarded nuclei.

Ex. 17. Read the text using a dictionary. Find the Subjective Infinitive Constructions:

When a nucleus of either ²³⁸U or ²³⁵U is split by the im­pact of a neutron, two atoms of other elements are found to be formed. These are elements which are located somewhere near the centre of the Periodic System, they usually being isotopes. These isotopes were stated to be temporarily un­stable, and therefore radioactive.

For example, the fission of a ²³⁸U nucleus appears to pro­duce one atom of barium and one of krypton; no less than thirty different elements have been identified in the course of recent experiments. The kind of elements formed is known to depend on how the uranium atom divides.

As might be expected of bodies accelerated by 200 mil­lion electron volts, these atoms have tremendous kinetic energy, and it is this energy which provides the blast effect or demolition force of the atomic bomb.

The energy released by fission is analogous to that pro­duced by the explosion of powder.

So, the atomic bomb’s destruction was said to be caused by the kinetic energy delivered by small particles moving at terrific speeds.

Ex. 18. Translate the text:

The advantage of a nuclear reactor is based on the lib­erated binding energy in the form of heat.

The disintegration is turned into a continuous process, a chain reaction is only due to the fact that the nuclei under fission eject neutrons which cause other fission in nuclei. The number of fissile material can be increased by slowing-down high-speed neutrons by collisions with atoms of such sub­stances which do not absorb them. Such moderators, e.g. iieavy water or graphite are necessary because, although

fast neutrons are not lost in the analysis, since they are absorbed by uranium 238, they are indispersible to maintain the chain reaction.

For the same reason, namely to keep neutron losses, reflectors, e.g. graphite and beryllium, are arranged at the ends of the active zone.

The nuclei of these reflectors are reported to repel the colliding neutrons without entering into a reaction with them.

Ex. 19. Read and translate the text:

If a few pounds of ²³⁵U or ²³⁹Pu were brought together suddenly into a small volume, the auto-catalytic fission of. the nuclei would occur nearly completely, and an amount Of energy would be released equal to that accompanying the detonation of about twenty thousand tons of a high explosive such as TNT. An ordinary atomic bomb is known to consist of a few pounds of ^23?U or ²³⁹Pu and a mechanism for suddenly compressing the metal. The process of nuclear fission is stated to liberate energy. The fission of a very heavy nucleus converts about 0.1% of its mass into energy.

Grammar: Revision. Text: Great Britain.

Ex. 1. Pronounce the following words:

textile ['tekstailj food [fu:d] town [taun] monarchy ['monoki] business f'biznis] fashionable ['faeJnabl] quarter I'kwoita] art [at]

gallery ['gaelari] store [sto:]

Ex. 2. Pronounce the following geographical names:

West End ['west 'end] East End ['i:st 'end] Liverpool I'hvapu:!]

Europe ['juorap]

North Sea ['no;0 'si:]

Gulf Stream ['длТ 'stri:m] Manchester ['maentj'ista] the Thames [бэ 'temz] Bristol ['bristlj

London [ЧлгМэп] Glasgow ['glccsgou]

Ex. 3. Pronounce the following word combinations:

an island country; three thousand feet; the inland water­ways; a great deal of; the rainfall in Britain; advanced in­dustrial country; world power; metal-working industry; by manufacture and trade; the Houses of Parliament; the House of Commons; fashionable quarters.

Ex. 4. Repeat the main forms of the following verbs:

to rise—rose—risen—rising to build—built—built—building to say—said—said—saying to grow—grew—grown—growing to lie—lay—lain—lying

Ex. 5. Translate the following sentences, mind the meanings of the verb “to do”:

1. They do not want to take part in this work as they are very busy. 2. The English do have their lunch between twelve and one o’clock. 3. What do you know about the City? 4. As they are interested in this work they try to do it very well. 5. Despite its high boiling point mercury does show a small vapour pressure even at ordinary temperatures.

6. Though the text was very difficult and there was little time for its translation they did translate it in time.

Ex. 6. Translate the following sentences, mind the Passive Infinitive:

1. This research work can be carried on in our new lab­oratory. 2. The production of consumer goods must be greatly increased next year. 3. This canal is known to have been built last year. 4. We know the new buildings of our Insti­tute to be built in two years. 5. They expect this investiga­tion to be carried out by young engineers. 6. This problem should be solved by the end of this month.

Ex. 7. Translate the following sentences:

Note: long — длинный length — длина no longer — больше не any longer — больше не at length — наконец

1. A long series of experiments are to be carried out be­fore we begin writing our report. 2. We know him to work

at this problem no longer. 3. There are many long rivers in the North of our country. 4. He has passed all his exams at length, and now he won’t stay in town any longer. 5. The length of this wire is not enough for our experiment.

Notes on the Text

1. A great deal of — много

2. ...Is engaged in industry...— заняты в промышленности

TEXT. GREAT BRJTAIN

Great Britain is an island country. It is separated from the continent of Europe by the English Channel and the North Sea.

The greater part of Britain is level. The highest moun­tains, which rise to a height of about three thousand feet, are in the North-West.

There are many rivers in Britain, but they are not long, the longest being the Thames. Many canals are known to have been built to connect the inland water ways.

Some parts of Great Britain are very beautiful and pic­turesque. In the mountainous North-West there are many fine lakes, this part being called the Lake District. There is a great deal of rain there. In general the rainfall in Great Britain is greater than in the rest of Europe. Due to the Gulf Stream the climate of Britain is mild and damp. The weather is very changeable.

Great Britain is the oldest capitalist country. In the 19th century it did become the most advanced industrial country in the world. Britain is no longer the world power that it was. Today it has a highly developed industry, the textile industry being the most important one. After it comes the metal-working industry.

Britain is known to be rich in coal, and iron ores. As for raw materials it has to import most of them from other coun­tries. Britain does not grow enough food to feed its popu­lation, it has to import the food. The people of Great Brit­ain are said to eat home-grown food only on one day of the week.

The majority of the working population of Great Britain is engaged in industry. Eighty per cent of its population lives in towns.

Britain is a parliamentary monarchy, but in practice it is governed by Parliament that consists of the House of _; Lords and the House of Commons.

j

London is the capital of Great Britain. London is one of the largest cities in the world. It stretches for nearly thirty miles from north to south, and for nearly thirty miles from east to west, this is known as “Greater London”.

The “City of London” is a very small part, it does cover only one square mile. The City is often called the commer­cial heart of London. Fleet Street, a well-known street in the City, is known as the home of British journalism.

London is a city of striking social contrasts. The West End which lies to the West of the City is the fashionable quarter of London. One can see the finest theatres, cinemas, concert halls, the largest museums, art galleries, best ho­tels, restaurants, the biggest shops and department stores there.

The East End of London is the district of factories and docks. Most of the people living there are workers. You won’t find big parks, green gardens, high comfortable houses there.

The sharp contrasts between London’s West End and London’s East End show the true face of a capitalist city.

There are many other big cities in Great Britain, most of them being ports, such as Liverpool which is the second largest port, Manchester, which is an inland port, Bristol, Glasgow and many others.

island to separate to rise (rose, risen) river

to connect lake

mountain

Ex. 8. Answer the following questions:

1. By what is Britain separated from Europe? 2. Where are the highest mountains in Britain? 3. What can you say about the rivers in Britain? 4. Where can you see many beau­tiful lakes? 5. What can you say about the climate in Great Britain? 6. When did Great Britain become an advanced industrial country? 7. What industries are mostly developed in Britain? 8. What mineral resources is Britain rich in?

9. Why has Great Britain to import raw materials? 10. What

Another interesting monument is St. Paul’s Cathedral.

Speaking about London, one should say, of course, about the Houses of Parliament. The Houses of Parliament are on the bank of the Thames, near Westminster Bridge.

The Clock Tower of the Houses of Parliament is called Big Ben, it being 313 feet high. The faces of the clock are very large. The minute-hand is 14 feet, the hour-hand is 9 feet long. The famous bell clock strikes every quarter of an hour.

Another well-known historic building is Westminster Abbey. For nearly a thousand years all the kings and queens of England have been crowned there. One part of the Abbey is known as Poet’s Corner, where many great writers and poets are buried: Charles Dickens, Thomas Hardy, Rudyard Kipling and some others.

Grammar: 1. Review of the Infinitive.

2. The use of once.

3. Review of only, the only, for. Text: Helium.

helium ['hirljomj slight [slait] earth [э:0]

terrestrial [tCrestrial] association [9,sousi'eiJan] fuel [fjuol] except [ik'sept] balloon [baTu:n] compare [кэт'реэ] explosion [iks'plougan] burn [born]

Ex. 2. Pronounce the following words; mind the stresses:

atmosphere f'aetmasfia] —atmospheric kaetmos'ferik] technology [ tek'nobdsi] — technological* [, tekna'hdsikal] molecule ['molikjurlj — molecular [mou'lekjulo] electricity [llek'trisiti] —electrical fi'lektrikol) vary ['veari]—variety [vo'raistij produce [pra'djurs] — production [pro'dAk/n]

Ex. 3. Read the following word combinations:

important constituent; in association with; technological uses; 93 per cent; helium molecule; easy to breathe; for electrical generators; in reality; widely distributed; the only sample.

Ex. 4. Translate the following sentences paying attention to the Sub­jective Infinitive Constructions:

1. The solubility of helium is stated to be much less than that of nitrogen. 2. Argon appears to be widely used for filling electric light bulbs. 3. The spectrum of the gas has been found to be the same as that observed before. 4. The amount of this substance was considered to have been of no practical importance. 5. Natural gas proves to contain a small percentage of argon. 6. This gas is stated to have found wide application in medicine. 7. These analyses turned out to have been of great importance for our research. 8. Our research-workers are reported to have finished their investi­gations in time. 9. Some materials are found to become readily charged and to hold their charges, while others are known to lose their charges very quickly.

Ex. 5. Translate the following sentences:

Note: once — как только, в том случае, однажды once — когда-то at once — тотчас, сразу once again — еще раз

1, Once collected heat can be used in a variety of ways.

2. Once it was thought that all the substances found in plants and animals could be made only by using of a living plant or animal. 3. He is to open the ventilating-hood at once.

4. Once carrying out his experiment the scientist noticed a very interesting phenomenon which later resulted in new discoveries. 5. Once absorbed the water was difficult to re­move. 6. Once formed bubbles rise to the surface. 7. If we consider the problem of evaporation once again, we shall easily explain these facts. 8. This work should be done at once. 9. Once a thermometer reactor is established there are some methods to obtain power. 10. Once the acidic properties were used to define an acid.

Ex. 6. Translate the sentences, mind the meanings of “only”, “the only”, “for”:

1. The only way to charge a body negatively is to add electrons to it. 2. Thus it is only the fastest molecules that

is Britain governed by? 11. What is the capital of Great Britain? 12. What do you know about London?

Ex. 9. Retell the text according to the following plan:

1. Great Britain is an island country.

2. Physical background of Britain.

3. Mineral resources.

4. Industry.

5. Political Structure of Great Britain.

6. The capital of Great Britain.

7. The City of London.

8. The West End of London.

9. The East End of London.

10. The Ports of Great Britain.

Ex. 10. Give the Russian equivalents of the following English words:

rainfall; world power; metal-working industry; home­grown food; in practice.

Ex. 11. Fill in the blanks with prepositions “of, “in”, “by”:

1. Our country is rich . . . coal, oil and iron ores. 2. There is a great deal . . . snow in the North . . . our country . . . winter. 3. . . . general this part . . . the country can be called agricultural one. 4. The highest mountains in Brit­ain are . . . the North-West. 5. . . . the 19th century Great Britain became the most advanced industrial country . . . the world. 6. . . . the East of Britain there is a low-lying district which is called the Fens. 7. . . . the South-East . . . England, is the county . . . Kent, there are many meadows and woods there.

Ex. 12. Translate the following sentences Into Russian, mind the In­finitives:

1. The copper to be used for electrical purposes must be extremely pure. 2. Many food products are known to be imported to Britain. 3. In the USSR many mineral resources can be found in the Urals, Kazakhstan, and some other places. 4. The iron ore in England is found to be low grade.

6. Iron to be protected from rust should be coated by zinc or cadmium. 6. Their task was to find out all the properties of this element. 7. We know the majority of the population of Britain to live in towns. 8. Metals which corrode easily are to be protected with a film of copper. 9. We expect them to have visited many cities of our country.

Ex. 13. Read the texts and retell them?

The USA is situated in the central part of the North Amer­ican continent. It is washed by the Pacific Ocean in the West, and by the Atlantic Ocean in the East.

The United States of America is a highly developed capitalist country. It is rich in mineral resources, espec­ially in iron, coal, gold, silver.

The USA is both a highly developed industrial and agri­cultural country. Speaking about industry we should say that such industries as motor-car industry, machine build­ing industry, food, textile, chemical industry, particularly the production of plastics, glass, dyestaffs, fertilizers, are highly developed. It should be mentioned that despite the fact that the USA is one of the advanced industrial countries its economy displays growing instability. The capitalist system creates growing chronic unemployment. Its economy suffers from constant crises.

The USA is a country of great contrasts: mineral re­sources, plants, banks belongtorich people, at the same time millions of people can’t find work, they live in poverty.

The USA is a federal republic. It consists of fifty states and the District of Columbia.

The White House is the residence of the President. The President is elected for four years. The country is governed by the Congress and the President. The Congress consists of two Houses, the House of Representatives and the Senate. Practically power belongs to the capitalists. The two friain parties are: the Republicans and the Democrats, their prog­rammes being almost the same. The only party which de­fends the interests of the working people is the Communist Party. The Communist Party of the USA was founded in 1919. The Communist Party is struggling against racial discrimination. It fights for peace, for peaceful coexistance with other countries.

The capital of the United States of America is Washing­ton. It is a big administrative and political centre. The White House, the residence of the President, is in Washing­ton.

2.

There are many places of interest in London. The Tower of London is the most famous historic building in London. For many centuries it guarded the entrance to London from the sea, now it is a museum.

are able to escape from a liquid surface. 3. The resistance of a conductor depends not only on its diameter and length but also on the kind of a substance involved. 4. Plastics having been discovered, cast iron was substituted for by plastics in many cases. 5. For purposes of illustration let us consider these gases. 6. They have used this substance for it is more soluble. 7. It is known that this great scientist gave up his brilliant career for a hard life of a researcher. 8. When liquid water becomes ice or steam there is no change in the chemical nature of the substance for the matter which makes steam and ice is the same in kind as that of liquid water. 9. For a long time this question couldn’t be solved.

9. A few metals, such as copper and mercury, form oxides only slowly, even when heated.

Ex. 7. Remember the meanings of the following prepositions:

instead of — вместо, вместо того, чтобы

despite — несмотря на

due to — благодаря, в силу, из-за

Notes on the Text

1. In association with — в связи с

2. Except for — за исключением

3. To face the problem — встать перед проблемой, столкнуться с про­блемой text. Helium

Helium is known to have been discovered in 1858 in the atmosphere of the sun, where it is an important constituent.

Slight amounts of it proved to be present in the earth’s atmosphere, the main terrestrial source of helium being mineral. It also occurs in association with the natural gas used for fuel.

It happens to be the lightest element except for hydro­gen. Helium is found to have a wide variety of technologi­cal uses. Its first common use was to lift balloons, its lifting power as compared with that of hydrogen being only 93 per cent, but it is safe from explosion and burning. As the he­lium molecule, which contains only 2 atoms, is so small the gas can be used as a detector of minute leaks in such small things as space capsules.

We know liquid helium to be used as a refrigerant. He­lium is also used as the inert gas instead of nitrogen. It re­places nitrogen in medical uses as it is lighter and thus easier to breathe. Helium is found to be used in a mixture with oxygen, the mixture being used as a synthetic atmosphere by the workers who have to work under high pressures.

Deposits that contain helium are mostly used for fuel. Helium is stated to be lost irretrievably. Scientists face the problem how to avoid the loss of helium which is so impor­tant.

From the standpoint of variety of its uses, helium is con­sidered to be the most important of the inert gases.

Despite the fact that its discovery was long delayed and that it was once believed to be very rare, in reality, this gas is widely distributed but in small amounts.

The scientists estimated helium to be present in the ex­tent of 0.0004 per cent by volume in the air and in various naturally occurring minerals and gases.

Remember the following words:

Ex. 8. Answer the following questions:

1. When was helium discovered? 2. Where can it be found?

3. Where is helium used? 4. What can helium molecules be used for? 5. Why is helium sometimes used instead of ni­trogen? 6. What problem do the scientists face? 7. Why is helium considered to be the most important of the inert gases?

Ex. 9. Find the right statement:

I. Helium was discovered in 1868

1. in the earth;

2. in the air;

3. in the atmosphere of the sun.

2. The first common use of helium was

1. to lift balloons;

2. to be a fuel.

Ex. 10. Translate the following words and state the suffixes of nouns:

discovery, variety, various, constitution, productivity, useful, usefulness, vary, consideration, considerable, dis­tribution, important, importance.

static ['staetikj dynamic [dai'naemik] kinetic [kai'netikj collaboration [ko^sebo'reijbri theoretician ^Giore'tijnj hypothetical [,haipo'0etikl] employ [im'pbi] vibrate [vai'breitj complexity [kam'pleksiti]

natural [Tiaetjral] deduce [di'dju:s] law [b:] imply [im'plai] absence ['sebsons] length [leij9j motion ['mouj^rn] equation [I'kwei/n] species ['spi:Ji:z]

bead [bi;d] manual ['maenjuol] subtract [sob'traekt]

Ex. 2. Read the following word combinations:

mathematical solution; the advent of the computer relatively few molecular properties; quantum mechanics dynamic processes; particular theoretical model; a variet of relative positions.

Ex. 3. Analyse the following pairs of sentences, translate the sentences into Russian:

I. Having constructed a new powerful chemical accel­erator, they could start their work.

A new powerful accelerator having been constructed, they started their work.

2. The electric computer simplifying greatly the calcula­tions, it is much easier now to find out all the proper­ties of new substances.

The electronic computer simplifying the calculations has been used in our laboratory.

2. A metal and non-metal combining transfer of electrons occurs with the formation of an ionic crystal.

A metal combining with a non-metal was investigated in our laboratory.

Ex. 4. Analyse the following sentences and translate them into Russian:

1. They suppose this method to be time-consuming and difficult. 2, The new method is supposed to be very interest­ing. 3. It is supposed that this new method can be widely used. 4. They found this machine to have been built at our plant. 5. This new device was found at our experimental shop. 6. They appeared quite unexpectedly. 7. They appeared to be wrong. 8. The students appeared to have finished

their work beforehand. 9. The text proved to be very diffi­cult. 10. It was proved that he was right. 11. They proved this method to have been useful.

Ex. 5. Translate the following sentences paying attention to the verb forms in bold type:

1. It would be very useful for you to attend all the lec­tures. 2. Were he free, he would attend these lectures. 3. If he had come in time, he would have been able to speak to this scientist. 4. It is necessary he should be present at this conference. 5. I think he could have done this work much better. 6. They suggested she should take part in this work.

6. She should have done this work in time, now it is too late.

7. If they wanted, they might come. 9. He would have come but he fell ill. 10. They would use these new accelerators but they can’t do it without him.

Ex. 6. Translate the following nouns:

rapidity, solubility, direction, absence, simplicity, in­vestigator, investigation, variety, definition, involvement, difficulty, relation, length, strength.

Ex. 7. Find the nouns and translate them into Russian:

relative, definition, gaseous, long, usefulness, useful, various, length, difficult, difficulty, greatly, strength, mo­tion, direction, direct.

Ex. 8. Translate the following sentences into Russian:

Note: even — даже

even — равный, одинаковый even — четный

1. This phenomenon is responsible for the fact that the absorption spectra even of gases at very low pressures con­sist of extremely narrow bands. 2. The first row of this table consists of even numbers. 3. This substance was difficult to dissolve even at a very high temperature. 4. Some sub­stances, even if present in insignificant quantities, greatly decrease the activity of the catalyst. 5. Before experimenting you should divide this substance into even portions.

Ex. 9. Translate the following v/ord combinations:

even figures; the rest of his days; the body is at rest; the rest part of; provided he works; he provides figures for the solution of the problem; the result of the work; it results in; present work; to present work; to be present at the lec­ture.

at least at last

Ex. 12. Open the brackets choosing a suitable word:

1. Helium was found to be an important (sample, constit­uent) of the atmosphere of the sun. 2. Helium is known to be used as the inert gas (in addition to, instead of) nitrogen.

3. Helium is said to be the (lightest, heaviest) element ex­cept for hydrogen. 4. Helium occurs in association with the (artificial, natural) gas used for fuel. 5. Helium can replace (hydrogen, nitrogen) in medical uses. 6. Helium is (present, absent) in various naturally occurring minerals.

Ex. 13. Find the sentences with the Objective Infinitive Constructions, translate all the sentences into Russian:

1. Helium, argon, neon, radon are known to be inert gases. 2. The scientists knew these gases to be inert. 3. The chemists found the existence of inert gases to have been scarcely suspected until the discovery of argon. 4. Helium, the lightest of the gases, is considered to have the properties which are very important. 5. A very few compounds of the inert gases appeared to have been reported at that time.

6. They found the atom of helium to contain only two el­ectrons of the first energy level. 7. Radon was found to be the heaviest of the inert gases. 8. Radon as have been stated by some scientists is known to be the direct disintegration product of radium. 9. This gas is to be found in the earth. 10. They believe the use of this element to result in many discoveries. 11. This element is believed to be widely used.

Ex. 14. Read and translate the text paying attention to the Infinitives:

The examination of the spectrum of the sun is known to have led to the discovery in the sun of a substance then un­known in terrestrial matter. This substance was named he­lium.

The amount of helium obtained then from uranium mi­nerals appeared to be of no great practical importance.

Having investigated the properties of helium, the scien­tists stated it to have the lowest density next to hydrogen. The solubility of helium was found to be much less than that of nitrogen.

Ex. 15. Retell the text:

Helium, the lightest of the inert gases, was discovered by W. Ramsay. The story of the discovery has its beginning in 1868, that year the French astronomer, Janssen discovered a brilliant yellow line which was unknown in the spectra of any of the terrestrial elements. This discovery is known also to have been made in the same year by Lockyer and Frankland.

The conclusion was that there existed in the sun an ele­ment not known on the earth. Lockyer gave to this new solar element the name helium, derived from the Greek word. Later another scientist showed helium to be present in the air though in very minute concentration.

Ex. 16. Listen to the tape-recorded text and retell it:

Elements

Element Number 1 is known to be a combination of one proton and one electron. Long before its atomic structure was known, this element was named hydrogen or “waterform- er”, the name being derived from Greek roots “hydro” and “gen” meaning “water” and “to be born”, because water forms when hydrogen burns in air.

Its symbol is H. Hydrogen has the first place in the list of elements because it has one proton in its nucleus.

Element Number 2 is found to consist of two protons plus two neutrons in the most common form and two elec­trons, it being called helium with the symbol He, from the Greek “helios”, “the sun”, because it was first identified in the solar spectrum before it was isolated on the earth. He­lium’s place in the list of elements is Number 2 because it has two protons in its nucleus.

LESSON 28

Grammar: Review of the Infinitive, Participle and the Sub­junctive Mood.

T e x t: Computer Experiments in Chemistry, Electronic Com­puters.

I

rapid ['rsepid] mechanics [mi'kaeniks]

electronic [ilek'tronik] enormously [I'nDimasli]

Notes on the Text

1 • ^r^St — ^в состоянии покоя 2. within the range — в пределах

Text. Computer experiments in chemistry, electronic computers

I

With the rapid evolution of electronic computers it would be natural to ask if they could provide mathematical solutions to problems in chemistry.

Before the advent of the computer relatively few mole­cular properties could be deduced directly from physical laws, they being mostly the properties whose definition implies the absence of atomic motions. An example of such a property is the length of the chemical bond between two atoms at rest.

When atomic motions are put into the equation, even in such an uncomplicated case as the transformation of one species of molecules into another in the gaseous state, the difficulty of the problem increases enormously.

For describing a simple reaction in a gas the equations of classical, or Newtonian, mechanics might be almost as useful as those of quantum mechanics.

The electronic computer is known to have greatly sim­plified the calculation of the static properties of molecules, bringing some of the dynamic processes within the range of mathematical investigation.

In the field of chemistry known as gas kinetics there has been a long collaboration between the experimental chemist working in the laboratory, and the theoretician, working with “models”, or hypothetical molecular systems.

As a result, some of our knowledge of rates and other properties of chemical reactions in gases appears to come from experiment and from theoretical analysis of simplified systems.

The computer is found to be employed not merely as a high-speed machine but as an experimental tool.

A computational experiment might involve solving the physical equations for particular theoretical model, to de­termine if its detailed properties could really conform to what chemists have always assumed.

Learning something about gas reactions seems to present great difficulties. Any reaction appears to involve at least

three atoms. They can have a variety of relative positions. If some of them were combined into a molecule, the mole­cule might vibrate and rotate. That’s why the complexity of the task can be solved by means of new computers. There are many types of computers used both for the investigation of physical and chemical properties. Many scientists are working at the invention of new types of computers.

II

The history of electronic computers proves the importance of their application in science.

Computers involved can be distinguished for the speed and accuracy of their operation, these two qualities having been realized in 1940’s. It should be mentioned that they were not suddenly realized, they being the product of a long historical development.

Electronic computers owe some of their earlier develop­ment to adding machines. One of the earliest adding ma­chines that we know is the abacus, a computing device that uses beads for counting, the beads being strung in groups of ten; the counting is known to be completely manual. Therefore, the speed of counting depends on the speed of the operator. In contrast, the early computing machines of Pascal and Leibniz were not completely manual. These machines employed a mechanical device for certain processes. This meant that the speed and accuracy of the particular process would not be completely limited by the speed and accuracy of the operator.

Pascal’s device, which added and subtracted, can be referred to as the prototype for other early calculators.

Later the scientists began searching for ways to develop j.a counting machine. Soviet engineers developed such ma- ’ chines which can automatically multiply and divide as well as subtract and add.

Scientific and technological progress requires the inven­tion and production of all types of machines. Soviet engi­neers use numerically controlled machine tools, robots and computers which help to raise productivity. They use com­puter facilities on a large scale to automate designing and research. The faster scientific and technological progress will enable to increase the growth rate of the national in­come. . -

Soviet society needs a faster scientific and technological progress which will enrich our people, both materially and culturally.

evolution computer to simplify as a result relatively

Ex. 10. Answer the following questions:

1. What can computers provide? 2. How could molecular properties be deduced before the advent of the computer?

2. What did the electronic computer greatly simplify? 4. Where did some of our knowledge of rates and other properties of chemical reactions in gases come from? 5. What might a computational experiment involve? 6. Where are electron­ic computers applied? 7. How can electronic computers be distinguished? 8. What is the earliest adding machine?

6. What does the speed of counting depend on? 10. What do you know about early computing machines of Pascal and Leibniz?

Ex. 11. Find the line in which there are only nouns:

1. rapid, use, absence, equation, law;

2. property, mostly, relative, greatly;

3. rate, properties, difficulty, analyses;

4. simplify, even, range, enormously.

Ex. 12. Choose the words which have the same form as nouns and verbs:

rate, range, provide, speed, direct, increase, rest, case, state, process, result, work, experiment, computer, model, rotate, task, analyse.

Ex. 13. Translate the following words of the same root:

assumption, assume; simplicity, simple, simplify; di­rect, direction, directly; vary, various, variety; deduce, deduction, deductive.

Ex. 14. State parts of speech the words in bold type belong to:

1. If we increase the temperature, gas will expand. 2. The increase in the production of synthetic materials was great­

ly affected by the creation of new types of machines. 3. These new machines provided all the necessary information for our work. 4. You would be able to use this new apparatus provided you are familiar with new technique. 5. Rubber acquires wide use in almost all branches of industry. 6. They use the electronic microscope when they have to detect tiny particles which the ordinary microscope fails to detect.

6. The solution of these mathematical tasks would be rather difficult without these computers. 8. The solution should be purified and then heated. 9. The results of his analyses were not yet clear, they had to be examined carefully. 10. So far, we have seen that this energy results from oxidation reaction and rearrangement of molecules. 11. In present work we should like to present the data of the analyses car­ried out in our new laboratory. 12. Speed is uniform when equal distance is passed over in an equal unit of time. 13. If the molecules of a substance are speeded up when heat is added, the temperature of the substance rises. 14. After their hard work they had rested before they started working again. 15. I carried out the rest of our work in the laboratory alone. 16. His work on using these accelerators in chemistry was very interesting. 17. He works hard as he wants to fi­nish his work as soon as possible.

Ex. 15. Find the English equivalents of the following Russian words and word combinations in the text;

математическое решение задач; непосредственно из физических законов; главным образом; между двумя ато­мами в состоянии покоя; даже в таком несложном случае; в области химии; в результате; по крайней мере; вот по­чему.

Ех. 16. Translate the sentences paying attention to the meanings of the word “rest”;

1. He devoted the rest of his life to the solution of this problem. 2. Having carried out a series of tedious experi­ments, they decided to have a rest. 3. We have learned that bodies do not change their state of rest or motion until some other body forces them to do so. 4. An object at rest is known to tend to stay at rest until a force is applied to make it move. 5. Both the state of rest and the state of motion are found to be changed due to some force. 6. He carried out the rest part of his work in the laboratory of the plant. 7. The rest part of this substance can be used in our experiment.

6. They rested their research work on the new methods dis­

7. covered by this professor. 9. The rest of his work was devoted to the investigation in the field of physics. 10. The final result is obviously for the rest the same in both cases.

Ex. 17. Analyse the following pairs of sentences, translate the sentences into Russian:

I. A number of new nuclear photochemical methods is known to be widely used.

Everybody knows a number of new nuclear photoche­mical methods to be widely used.

2. The simplest imaginable way to accelerate a molecule into the electrovolt range is supposed to be mechanical. They supposed the simplest imaginable way to acce­lerate a molecule into the electrovolt range to be me­chanical.

3. The work on the energy dependence of the reactions between ionized molecules was found to have been done with the help of modified mass spectrometers.

They found the work on the energy dependence of the reactions between ionized molecules to have been done with the help of modified mass spectrometers.

Ex. 18. Translate the following sentences, mind the verb forms:

1. Having examined the properties, they could continue their work. 2. Examining the static properties of molecules helped them in their work. 3. The properties examined by the electronic computer were very important. 4. The com­puter employed in our laboratory, was very good. 5. The computer having been employed, they could finish their work in time. 6. Employing the computer they could make very important calculations.

having worked out the plan working out the plan the process described in the article

describing the process having described the process

Ех. 20. Find the sentences in which “should” and “would” are used to express the Subjunctive Mood:

1. They said they would use this computer. 2. When they worked at the plant they would often use your methods in their work. 3. He would tell us about the design of this new electronic computer but unfortunately he is very busy now.

2. It is necessary that this method should be simplified.

3. We said that we should take part in this investigation.

4. They knew that the difficulty of the problem would in­crease enormously if they didn’t use the new design. 7. He suggested that this new method should be examined in their laboratory. 8. This engineer would have told you about his new experimental work if you had asked him.

Ex. 21. Translate the text using a dictionary:

One of the amazing things about computing machinery is that although it is designed and programmed by human minds, its abilities often surpass those of its inventors.

A striking example is the application of artificial intel­ligence in the analysis of chemical data, this method being applied at some laboratories.

The scientists believe this method to find wide appli­cation in the solution of problems which chemists can’t solve now. This method appears to confront a problem basic to all sciences.

Ex. 22. Listen to the tape-recorded text and discuss it:

Modern technology puts steadily increasing demands to the quality of alloys and steel. This depends on the mi­crostructure of the metal, the order in which its crystals occur, and the orientation of the crystalline grains in poly­crystals. This quality can be improved if we learn how to measure the deficiencies in the “packing” of the crystals and control the quality of the metal we produce.

Now, there are two tested methods. One is the optical, using powerful microscopes, and the other is the X-ray tech­nique. Both involve considerable practical difficulties and cannot be applied in all cases, for example, when dealing with coarse-grained materials. Of course, one can use instead a magnetic texturemeter, as specialists here call it. It can distinguish very fine characteristics of motion in a material placed in a strong magnetic field. But the instrument in its traditional form is far too clumsy, consisting of two sections, one weighing 100 and the other 20 kilograms.

Experts of the Institute of Metal Physics at the Urals Research Center of the USSR Academy of Sciences have now developed their own version of this instrument which is much smaller and easy to use. The new instrument weighs only 5 kilograms, and now it takes less than one minute to measure a metal sample with it. The new instrument was

awarded a Gold Medal of the 1984 Leipzig Fair. It is now used at metallurgical works in the Soviet Union and other socialist countries.

• ! —

Grammar: 1. Revision of the Infinitive Constructions.

2. Revision of the Perfect Tenses.

3. The use of few, a few, little, a little.

Text: The .Microbiological Production of Industrial Chemicals.

microbiological ['maikro(u)- bam'bdsikol] capability [,keipa'biliti] microorganism ['maikro'orga- nizm]

pharmaceutical [,fam9'sju:- tiklj

serve [so:v]

lubricant ['l(j)u;brikont] extractant [iks'traektont] adhesive [ed'hiisiv]

Ex. 2. Practise the reading of the following word combinations:

surface coatings; in microbiological fermentation; the chief raw material; chemical synthesis; the product from the fermentation medium; the synthetic-chemicals industry; the advantage of an abundant and inexpensive feedstock.

Ex. 3. Read the following word combinations and translate them into Russian:

industrial chemicals; either biologically or by chemical synthesis; a major consideration; the principal raw mate­rial; the process must be taken into consideration; commer­cial value; particular substrate molecule.

Ex. 4. Translate the following sentences, mind the meaning of “few”, “a few”, “little”, “a little”:

1. With few exceptions, construction materials are solid materials or harden into solid materials. 2. When the com­pass is placed successively at a few points in the vicinity of the bar magnet the compass needle alines itself with the field at each position. 3. We have got little information

about this new discovery. 4. Since little air is fed to the lower column in liquid form, start-up requires some kind of special program. 5. For a few uses requiring rigidity, aluminum must be alloyed with one or other elements, chiefly magnesium. 6. A little water should be added to make this substance melt. 7. A few years ago a new device was invented at our research institute, now it being used at a few plants. 8. As I had little time I couldn’t get reliable figures, Г11 have to carry out the experiment again. 9. There is little ink in the ink-stand, I can’t write. 10. There are few uses of this metal in industry.

Ex. 5. Translate the following sentences into Russian, mind the tenses of the Predicate:

1. For nearly a century the scientists working with food have been trying to understand more fully the role of mi­croorganisms in fermentation. 2. The rising cost of petroleum has made the product less competitive. 3. The introduction of microbiology into the pharmaceutical industry has bro­ught about a transformation profound enough to be called a revolution. 4. They have been working at the problem involved since 1980, but still much is to be done. 5. Re­cently it has become widely accepted to use this technique in determining the weight of some substances. 6. This view of conservation laws has been radically changed by the de­velopment of the modern theories of elementary-particle interraction. 7. He had been carrying out the experiment for two hours when I came into the laboratory. 8. They have been working out the new procedure for at least a month, they will have to begin their experiments. 9. A great number of foreign scientists have visited our laboratory as it is con­sidered to be the best one in our Research Institute. 10. A lot of workers have been attending these courses to get acquaint­ed with the new methods of producing some products from different chemicals. 11. Our chemists have solved a great number of urgent problems in the field of environmental protection lately. 12. I was asked how long I had been work­ing at that plant. 13. The new apparatus had already been installed in our shop by the end of November. 14. The work hasn’t been finished yet, we have to continue experimenting. 15. Unfortunately I haven’t been to Leningrad since I gra­duated from the Institute.

Ex. 6. Translate the following sentences into English, mind the use of the tenses:

1. Он посещает лекции по химии с сентября. 2. Он по­сетил несколько лекций с сентября. 3. В прошлом году он посетил несколько лекций по общей химии. 4. К де­кабрю он провел целую серию экспериментов. 5. Когда я приступил к работе, он уже закончил эксперименты.

6. Он изучает физическую химию уже три года. 7. Недавно мы посетили выставку «ХИМИЯ-86». Она произвела на нас очень большое впечатление. 8. В прошлом году мы посетили ряд химических заводов. 9. Когда я вошел в лабораторию, он уже проводил опыт в течение часа. 10. Ко­гда я вошел в зал, докладчик говорил о развитии химии полимеров в нашей стране.

Ех. 7. Translate the following sentences into Russian, mind the Infi­nitive Constructions:

1. Thousands of years ago stars were believed to govern the fate of men. 2. Scientists are known to agree that our universe is fundamentally dependent on two factors, one of which proves to be matter, the other energy. 3. The scien­tist found the atom to have, first of all a nucleus; the nuc­leus was found to be composed of the protons and neutrons.

4. Of all the available building materials, rock and stone are known to be traditionally associated with permanence.

5. The organic materials with the notable exception of wood appeared to be largely a development of the twentieth cen­tury. 6. We know metals to be extracted from natural ores, which of course are also ceramic materials. 7. The metals turn out not to be as hard as the ceramic materials, but ceramic materials have been stated to be very brittle. 8. Al­though neither hydrogen nor helium proved to be now com­mercially produced from air, it is appropriate to mention that neither liquid hydrogen nor liquid helium can be trans­ported in the type of equipment used for liquid oxygen, ni­trogen, and argon. 9. As the field of chemical engineering developed, physical operations have been found to be con­venient to classify into a number of “Unit Operations”, which could be separately studied and investigated.

Notes on the Text

1. To put it another way — другими словами

2. In conjunction with — вместе, сообща text. The microbiological production of industrial chemicals

The synthetic capabilities of microorganisms are not confined to food, drink and pharmaceuticals. Microorganisms are known also to produce industrial chemicals that can eith­er serve as or be employed to make solvents, lubricants, extractants, adhesives, plastics, surface coatings, explo­sives, etc. Often an organic substance with industrial appli­cations can be made either biologically or by chemical syn­thesis, the decision to make it one way or the other being essentially an economic one. A major consideration proves to be the cost of the raw materials. In microbiological fer­mentation the chief raw material has been found to be the growth substrate, it usually being starch. In chemical synth­esis the principal raw material has been found to be petro­leum or a derivative of it. The efficiency of the process must be taken into account. Another factor to be taken into ac­count is the cost of recovering the product from the fermen­tation medium. One must also weigh the potential value of by-products, and the cost of disposing wastes.

Microorganisms are known to produce some 200 sub­stances of commercial value, only a few of them being cur­rently made by biological methods in industry, they in­clude ethanol, n-butanol, aceton, acetic acid, amino acids and enzymes. Scientists consider microorganisms to have a larger role in many industries. With the new genetic meth­ods the microbiologists and chemists are able to replace an existing pathway with a new one. To put it another way, they can construct organisms that have new characteristics and capabilities. Thus microbiological fermentation in conjunction with the new techniques could contribute sig­nificantly to the production of three broad classes of indus­trial chemicals: aliphatic organic compounds, amino acids, and enzymes.

Enzymes can catalyze both the making and the braking of chemical bonds. Each enzyme is stated to act only on a particular substrate molecule.

Commercially produced enzymes are playing an increas­ing role in medical diagnosis.

Microorganisms have been studied thoroughly but still much is to be studied.

Remember the following words and word combinations:

to confine cost feedstock

to serve substrate finite

pressures we must consider the concentration or activity of hydrogen ions (pH).

Biochemical reactions can proceed only if certain energy requirements are met. The primary source of energy on our planet has been solar radiation. A part of this energy is known to be stored as chemical energy in the bonds of va­rious compounds. Most of the energy required for maintain­ing the structure of living systems derives from oxidation— reduction processes particularly from the oxidation of hy­drogen by atmospheric oxygen.

Biochemical reactions proceed at a rate that depends on the concentration of the reacting molecules and on the rate constants characterizing the given type of reaction. This rate can be increased in living systems by the presence of catalysts (enzymes).

Grammar: Review of the Subjunctive Mood and Adverbial Clauses of Condition.

Text: The Chemical Elements Essential to Life.

certainty ['so:tnti] growth [grouO] fluorine ['fluarimj biologist [bai'obdgist] organism ['э:дэшгт] crust [krAstJ potassium [po'taesjam] magnesium [masg'niiziam] versatility [,V3:so'tiliti]

Ex. 2. Read the following words and word combinations:

with certainty; since then; for the growth; living orga­nisms; atmosphere; in the earth; essentially; non-existent; 98 per cent; unique ability; constituents of the molecules; minute quantities.

Ex. 3. Translate the sentences into Russian, mind the Infinitives and Infinitive Constructions*.

1. A. S. Popov is known to have demonstrated his inven­tion in 1895. 2. The material to be analysed was cleaned

and dried. 3. The scientists expected these elements to be essential for life. 4. These materials are believed to be used in the aviation industry as they are very durable. 5. This new plant proved to be one of the greatest plants in our region. 6. Nitrogen compounds principally as proteins are found to be essential constituents of all living organisms.

6. Their first task was to synthesize some new elements.

7. The natural organic polymers from which things are made appear to include proteins, cellulose and some other classes of compounds. 9. In ancient times some liquids were be­lieved to have power to dissolve all things. 10. Eight elements seemed to provide more than 98 per cent of the atoms in the earth’s crust.

Ex. 4. Translate the following sentences paying attention to the Sub­junctive Mood and Adverbial Clauses of Condition:

1. Free silicon might be expected to be produced both in laboratory and in industry. 2. This question couldn’t be answered with certainty if you didn’t carry out a number of investigations. 3. If this research had been done earlier, the role of this element would have been clear. 4. This ele­ment could be predicted if you knew the properties of the other elements. 5. Were all the properties known, it would be much easier to use this element. 6. Nitrogen itself is known to be inactive. If the atmosphere contained much more than the normal amount of it, the chemical activity of the oxygen, an active ingredient of air would be too much retarded. 7. Had the laboratory been repaired in time, we should have finished our research much earlier. 8. It would be interesting to find out all the properties of these elements.

6. It is necessary that all the properties of these elements be investigated before we start experiments.

Ex. 5. Translate the sentences into Russian:

case—случаи the c^se is—дело в том in no case—ни в коем случае in case—в случае, если in any case—во всяком (лю­бом) случае

account — описание; отчет, доклад

1. In case of the atomic explosion the energy is known to be liberated in the form of heat and radiation. 2. Ordi­

nary glass in no case transmits ultraviolet rays owing to the iron oxide contained in it. 3. In other case, the decay into radicals is slower than that of the molecules. 4. In the case of gaseous substances this phenomenon can be attributed to dissociation. 5. The case is that the cement mixture is prepared artificially from lime stone. 6. In most cases of this kind the mutual solubility of the liquid increases. 7. In case the plates of the charge storage battery are connected by means of a conductor the current begins to flow. 8. An alpha particle (whose mass is 4 and whose charge is + 2) may be expelled as is the case with naturally occurring radioactive elements. 9. He will finish his work in any case, though he is very busy. 10. How can we account for the exis­tence of neutrons? 11. If the gas is collected over water, the pressure due to water vapour must be taken into account.

12. To complete the account of the transition series of the first long period it is necessary to say about copper and zinc. 13. On account of the resistance of tin to the action of air and water it is used to coat other metals. 14. All the accounts of their experimental work were completed in time. 15. The laboratory was under repair, on this account they couldn’t finish their experiments.

Ex. 6. Read the following word combinations:

naturally occurring elements; exactly defined limits; extremely difficult task; rarely met elements; hardly pos­sible task; highly soluble substance; nearly non-existent mixture.

Ex. 7. Translate the following sentences paying attention to the mean­ings of the word “way”:

1. In this way he succeeded in obtaining chemically pure forms of this substance. 2. Scientific and engineering thought is occupied with the problem of obtaining iron by way of direct reduction from its ores. 3. Platinum is a white lust­rous metal which in no way changes in the air even if heated very intensively. 4. The engineers have placed a compres­sorless turbine with a power generator in the way of the hot gas stream leaving the furnace. 5. Physical properties of water are strikingly different from those of other substances in ways that determine the nature of physical and biological world. 6. An electron may act like a proton in some way.

2. The experiments were carried out in such a way that the exchange of the final deutron was measured. 8. We are deal­ing with 2 opposing reactions, each of which is taking place n such a way that the other can occur at the same time. ). In this way, repeated distillation may be eliminated and :he separation may be accomplished in a single operation.

6. The way was very difficult and they could hardly reach :he place late in the evening. 11. This explains by the way ;he use of those elements in light industry.

Notes on the Text

1. building-block — зд. основа

2. to set a limit — установить предел

3. to be responsible for — обусловливать, быть причиной

4. living matter — живая материя

5. in no way — никоим образом

Text. The chemical elements essential to life

How many of the naturally occurring elements are es­sential to life? After more than a century of investigation the question still cannot be answered with certainty.

Only some time ago the best answer would have been twenty. Since then four more elements have been shown to be essential for life, for example, for the growth of animals, such as fluorine, silicon, tin, and vanadium.

Nickel is thought by the scientists soon to be added to the list.

In many cases the exact role played by these elements would remain unknown or unclear. Both chemists and bio­logists have long been surprised by the way the evolution has selected certain elements as the building-blocks of liv­ing organisms.

Thus the composition of the earth and its atmosphere obviously sets a limit on what elements are available.

The solar system, like the universe, seems to be 99 per cent hydrogen and helium. In the earth’s crust helium ap­pears to be essentially non-existent, except in a few rare deposits, hydrogen atoms constituting only 22 per cent of the total.

Eight elements provide more than 98 per cent of the atoms in the earth’s crust, namely oxygen 47 per cent, silicon 28 per cent, aluminium 7.9 per cent, iron 4.5 per cent, cal­cium 3.5 per cent, sodium 2.5 per cent, potassium 2.5 per cent, magnesium 2.2 per cent.

to employ

lubricants

adhesives

coatings

essential

major

1. What does this text deal with? 2. What do microor­ganisms produce? 3. How can an organic substance with industrial applications be made? 4. What is the major con­sideration? 5. What is the chief raw material in microbio­logical fermentation? 6. What is the principal raw material in chemical synthesis? 7. How many substances are known to be produced by microorganisms? 8. What do scientists think about microorganisms? 9. What three broad classes of industrial chemicals do you know? 10. What do you know about enzymes?

Ex. 9. State to what part of speech the following words belong according to their suffixes and translate the words into Russian:

capability, production, industrial, employ, apply, ap­plication, essentially, usual, usually, efficiency, special, specificity, impractical, decision, principal.

Ex. 10. Translate the following text into Russian, mind the Infinitive Constructions:

The second major class of industrial chemicals is known to be made up of aliphatic organic compounds, which prove to be distinguished by the absence of benzene rings and similar structures. The aliphatic substances with indus­trial applications can be broadly divided into two cate­gories; solvents and organic acids. The solvents were found to include ethanol, n-butanol, acetone and glycerol; the organic acids have been found by the scientists to include acetic acid, citric acid and lactic acid.

In general the scientists found the solvents not to be made by biological means, although n-butanol, acetone and gly­cerol were once made that way. Nevertheless, the solvent industry may return to fermentation because of the cost of petrochemicals, the prospect of exploiting thermophilic bacteria and the availability of new feedstocks.

Thermophilic bacteria have been stated to grow rapidly in the range of temperatures between 60° and 75°C. We found their chief advantage over microorganisms to be their faster metabolism.

Ex. 11. Translate the text in written form, mind the tenses:

The introduction of microbiology into the pharmaceu­tical industry which began in the 1940’s has brought about a transformation profound enough to be called a revolution. Advances in our understanding of microorganisms and tech­niques are now exploited in the identification of new thera­peutic substances, in research and development and in the processes of industrial production itself. The linked chemical reactions that have made up the metabolic system of a mi­croorganism constitute the means of production. In huge tanks cultures of genetically identical cells bred for high yield are immersed in a rich liquid medium. The pharma­ceutically valuable products of metabolism are being ex­tracted and subjected to further processing.

Ex. 12. Translate from Russian into English, use Subjective and Ob­jective Infinitive Constructions:

1. Известно, что в последнее время фармацевтическая промышленность значительно развилась. 2. Было уста­новлено, что этанол является одним из наиболее важных органических химикатов в этой промышленности. 3. Мы знаем, что эта статья посвящена развитию микробиологии в нашей стране. 4. Оказалось, что стоимость производства этих веществ очень велика. 5. Известно, что научные сотрудники нашего института провели серию эксперимен­тов, используя органический растворитель — бутанол и получили хорошие результаты. 6. Этот метод, по-види­мому, старый и не дает хороших результатов. 7. Они знали, что опыты были закончены и результаты были удовлет­ворительными. 8. Обнаружено, что из промышленных кислот уксусная кислота является самой важной. 9. Этот .растворитель, по-видимому, не может быть использован в нашей отрасли.

Ех. 13. Listen to the following tape-recorded text and retell it in Russian:

We know biochemistry to be described as chemistry of living objects (cells and organisms). Living objects are stat­ed to differ from inanimate ones in their ability: a) to me­tabolize and b) to transmit genetic information.

They are governed by all the principal laws of nature, such as the law of conservation of mass and energy and the law of thermodynamics.

Biochemical reactions are considered to take place with­in a relatively narrow range of physical and chemical par­ameters. Besides the limited range of temperatures and

Of these eight elements only five are among the eleven that account for more than 99.9 per cent of the atoms in the human body.

Two elements, hydrogen and oxygen, account for 88.5 per cent of the atoms in the human body, hydrogen supply­ing 63 per cent of the total and oxygen 25.5 per cent.

Carbon accounts for another 9.5 per cent and nitrogen 1.4 per cent. The remaining 20 elements now thought to be essential for life account for less than 7 per cent of the body’s atoms.

Silicon is known to be 146 times more plentiful than carbon in the earth’s crust. Silicon like carbon has the ca­pacity to gain four electrons and form four covalent bonds. Carbon was selected over silicon as the central building- block. The difference that led to the preference for carbon compounds over silicon compounds can be explained: 1) by the unusual stability of carbon dioxide, and 2) by almost unique ability of carbon to form long chains and stable rings with five or six members.

The versatility of the carbon atom is responsible for the millions of organic compounds found on the earth.

If some generalization were made about the role of va­rious elements it would be interesting to note that six ele­ments carbon, nitrogen, hydrogen, oxygen, phosphorus and sulphur make up the molecular building-blocks of living matter: amino acids, sugars, fatty acids, purines, pyrimidi­nes and nucleotides.

These molecules not only have independent biochemical roles but also are the constituents of the following large mo­lecules: proteins, glycogen, starch, lipids, and nucleic acids. This is the first essential group.

The electrochemical properties of living matter depend on elements or combination of elements that either gain or lose electrons when they are dissolved in water, thus forming ions.

The principal positively charged ions are provided by four metals; sodium, potassium, calcium and magnesium. The principal anions (ions with negative charge) are pro­vided by the chloride ion, sulphur, and phosphorus. These seven ions maintain the electrical neutrality of a body fluid and cells. This is considered to be the second essential group. The third group of essential elements consists of the trace elements. The fact that they are required in extremely mi­nute quantities in no way diminishes their great importance.

Ex. 8, Answer the following questions. (Work in pairs.)

1. Is it possible to answer the question about the number of naturally occurring elements with certainty? 2. What have the chemists and biologists long been surprised by?

3. What does the solar system consist of? 4. Is there much helium in the earth crust? 5. What eight elements can pro­vide more than 98 per cent of the atoms in the earth’s crust?

5. What two elements account for 88.5 per cent of the atoms in the human body? 7. What element is more plentiful, silicon or carbon? 8. What elements make up the molecular building-blocks of living matter? 9. What do the electro­chemical properties of living matter depend on? 10. What ions maintain the electrical neutrality of a body?

Ex. 9. Find the correct answer to the following question:

What elements make up the molecular building-blocks of living matter?

1. Sulphur and phosphorus make up the molecular building-blocks of living matter.

2. Carbon and nitrogen make up the molecular building- blocks of living matter.

3. Six elements, namely carbon, nitrogen, hydrogen, oxygen, phosphorus and sulphur, make up the mo­lecular building-blocks of living matter.

Ex. 10. Find the pairs of synonyms and remember them:

lately, to account for, recently, essential, to provide, to explain, to supply, amount, important, quantity.

Ex. 11. Find the pairs of antonyms and remember them:

existent, clear, disappear, negative, unlike/ charge, appear, like, stable, to gain, artificial, unclear, unstable, to lose, discharge, positive, non-existent, natural.

Ex. 12. Translate the following sentences paying attention to the mean­ings of the word “provide”:

1. The steel may be provided with the desired degree of hardness depending on the temperature to which it is reheat-

ed. 2. To provide the laboratory with necessary equipment much money should be spent. 3. Our new laboratory is pro­vided with gas and running water. 4. The materials provided by nature can no longer satisfy the rapidly developing tech­nology. 5. The mass spectrum can be used to provide unique information concerning the molecular structure of some unknown compounds. 6. This type of information provided by this technique is new. 7. They will apply these new meth­ods provided they are effective enough.

Ex. 13. Translate the text, mind the Infinitives:

Analyses of the strengths of the dark absorption lines in the spectra of the stars and of the sun have shown hydrogen and helium to be the most abundant in the universe.

The scientists found normal stars to contain two-third by mass of hydrogen and one-third by mass of helium, all the other elements together amounting to about 2 per cent by mass.

The next three elements—lithium, beryllium, boron appear to be very rare. The following three elements—-car­bon, nitrogen, oxygen are known to account for most of the above 2 per cent.

Ex. 14. Translate the text, mind the Adverbial Clauses of Condition and Subjunctive Mood:

Very pure solutions of hypochlorous acid might be pre­pared from its anhydride. If less pure solution were to be prepared, it could be done by one of the following methods:

1. The acid might be prepared if chlorine were passed into a suspension of finely divided calcium carbonate. Pre­sumably, chlorine would be again hydrolyzed but the re­latively insoluble carbonate would be attacked only by the stronger acid, HC1.

2. If chlorine were passed into a cold solution of sodium hydroxide, a mixture of the chloride and hypochloride of sodium would be formed. If the solution had been treated with a weak acid or with a very dilute solution of one of the stronger acids, weakly ionized hypochlorous acid would have been formed.

Ex. 15. Open the brackets translating the Russian words into English:

1. A temperature change (будет причиной) volume chan­ges in concrete. 2. No attempt was made (объяснить) asym­metry of the spectrum. 3. In developing this theory the Chemical stability of noble gas atoms (была принята во

(внимание). 4. (В случае) of bad results the experiment is to be carried out again. 5. The solution will be evaporated (при условии) the temperature is very high. 6. They (обес­печили) us with all glassware necessary for this test. 7. (Та­ким образом) the element was extracted without any dif­ficulty. 8. This (случай) was difficult and we couldn’t ex­plain it. 9. They can (едва) fulfil this test without his help.

Ex. 16. Retell the text:

Hydrogen is known to be the lightest of the elements. If the temperature is 20°C, it is a colourless, odourless, taste­less gas, its density being 0.08987, i.e. 1/15 that of air.

Hydrogen was liquefied. The device used for it proved to be similar to that used in liquefying air. The gas is only slightly soluble in water, its solubility under standard pres­sure in 100 ml of water being 1.93 ml at 0°.

Hydrogen could be found in the free state only in minute quantities because of its marked chemical activity. It is known to be prepared in the laboratory by its liberation from acids, bases, or water.

Ex. 17. Listen to the following tape-recorded text and render it:

Specialists consider hydrogen to be an extremely promis­ing energy source. The reserves of hydrogen are known to be practically unlimited, it containing almost three times more thermal energy than benzene. Another plus is that hydrogen can be used as fuel in transport, industry and at home.

Extensive use of hydrogen as an energy source will help keep the environment clean—hydrogen combustion pro­duces simply the vapour of distilled water.

Hydrogen is easy to transport and store. It could be shipped over large distances using conventional pipe-lines.

Even today, it costs several times less to transport hy­drogen by pipe-lines than to transmit electricity across huge power lines. Like any other gaseous fuel it could be accu­mulated and kept for a long time either in conventional or natural reservoirs.

Scientists have found many ways of producing hydrogen on a commercial scale—basically from ordinary water. Large volumes of this fuel could be obtained from coal, its reserves being tremendous.

15—893 Щ

Grammar: Review of the Infinitive and Nominative Abso­lute Construction.

Text: Pollution.

humanity [hjui'mzeniti] automobile ['э^этэЫ:1] environmental [ш,уаюг(э)п- 'ment(3)l] chimney ['tjimni] furnace j'fomis] incompletely [,ткэт'рН:Ш] unburned ['лп'Ьэ-'nd] negligible ['neglidg^bl] lime [laiin]

Portland ['poitlend] cement [si'ment]

Ex. 2. Read the following word combinations:

industrial activity; environmental protection; funda­mental principles; unburned carbon; mineral content; lead bromide; exhaust of automobiles; urban areas; earth's sur­face; carbon monoxide; extensive damage; ocean water; discharged gases; extensive measures.

Ex. 3. Translate the following words paying attention to the su/fixe$[

industry, industrial, active, activity, use, useful, use­fulness, useless, important, importance, current, currently, principle, principles, main, mainly, incomplete, incom­pletely, nature, natural, chemical, chemicals, consideration, considerable, extensively, addition, additional, harmful, harm, valuable.

Ex. 4. Repeat the meaning of the following verbs:

to give off to give out to give up

to turn off to set up

to turn out

to find to concern

to find out to be concerned with

Ex. 5. Translate the following sentences into Russian, mind the words in bold type:

1. The present figures are not enough to complete this work. 2. They had to present all the available data by the end of the year. 3. Everyone who was present at the confer­ence should present their reports. 4. They caused the ma­chine start working. 5. The cause of his failure can be easily understood. 6. The tasks to be solved at our conference are of great significance. 7. If you heat this substance it can be solved very soon. 8. The use of natural gas is of great help in reducing pollution. 9. If the weather is fine the plane will land at 5 p.m. 10. The pollution of the land mass is to be investigated very thoroughly.

Ex. 6. Translate the following sentences into Russian:

1. The problem to be solved deals with environmental protection. 2. Some chemical processes to be considered were of great importance. 3. Raw materials to be used for manufacture of some chemicals can be obtained in this re­gion. 4. The discovery to be made in the field of nuclear physics was of great value. 5. The substances to be purified should be carefully treated. 6. The lecture to be followed by the experiment was devoted to pollution. 7. The figures to be referred to should be arranged in the table.

Ex. 7. Give the Russian equivalents to the following word combinations:

the matter of great concern; as a whole; in addition to; to pay attention to; to go into service; as a result; either . . . or; to take care of; constant care; consuming materials. Ex. 8. Repeat the following verbs:

to spend—spent—spent to lay—laid—laid to burn—burnt—burnt to find—found—found to study—studied—studied to set—set—set

Text. Pollutson

Pollution is known to be of great concern to both science, industry and to humanity as a whole.

There has always been pollution, even when man was not present. When man appeared upon earth, he added much to the pollution. As the population of man on earth increased, pollution increased too, it being increased in three waysi

through the numbers of persons, through the industrial ac­tivity, and through man’s use of devices such as automobiles that cause pollution. One of the most important tasks to be solved is air pollution. The Soviet Union is currently spending a great sum of money on environmental protection, the fundamental principles of environmental protection being laid down in the constitution.

The study of pollution could be divided into three main parts: pollution of the air, of water and of the land mass. To study this problem is very important for man.

Air Pollution

Every smoking chimney turns out to be a source of air pollution. Home furnaces tended to; burn soft coal incom­pletely, thus adding unburned carbon particles to the air.

The use of natural gas or oil that have a negligible min­eral content is of great help in reducing pollution, but has the disadvantage of rapidly consuming materials which could better be conserved for future generation as raw ma­terials for the manufacture, for example, chemicals and plastics.

It has been found that some chemical processes, such as the manufacture of lime, Portland cement, steel, tend to give off much dust.

Lead, bromide and chloride emitted from the exhaust of automobiles which burn lead-containing gasoline pro­duce a lead-chloride-bromide aerosol which is considered to be a common air contaminant in urban areas, it being toxic to people. The chief atmospheric gaseous pollutants originating from the earth’s surface appeared to be ojydes of sulphur, oxides of nitrogen, incompletely burned hydro­carbons, and carbon monoxide.

These gases are known to react with energy from sunlight to produce photochemical smog. Smog not only can be highly irritating to eyes and lungs, but it can also cause extensive damage to vegetation?

There are many problems to be solved concerning the pollution of air.

Water Pollution

Some cities simply run their raw sewage directly into nearby natural waters. This is one of the worst types of water pollution. .

Another type of pollution of sea and ocean water is pe­troleum oil, it taking place in connection with off-shore drilling operations. It should be also noted that unfortu­nately there is as yet no satisfactory method of overcoming the effects of oil spills, although many methods have been tried.

Earth Pollution

In addition to air and water, the solid part of the earth is also in danger from pollution. Solid wastes include such things as: metal cans, glass bottles, plastic containers, ashes from the combustion of coal and wood, and radioactive isotopes. The problems created by pollution are very diffi­cult, but fortunately great progress is being made in their solution.

The Soviet Union plans to protect the land, its mineral and water resources, plants and animals. The'atmosphere over cities is the object of constant care and attention on the part of the government. Each year steps are taken to improve the protection of the atmosphere from harmful factory pollution.

Hundreds of new devices tovtrap and neutralize the harm­ful substances contained in discharged gases go into service. As a result, in more than 70 per cent of cities where the air monitored, discharges of dust, sulphur gases and hydrogen sulphide were either stabilized or reduced altogether, harmful industrial pollution of the air of cities and industrial centres having been greatly diminished throughout the country.

Extensive measures are being taken to set up reserva­tions and carry through biotechnical measures for-the pro­tection and reproduction of species of animals, birds and valuable fish.

Much money is being spent, but it should be noted that money alone is not enough to protect the environment. The attitude of people is vital and much depends on the people.

There will never be complete success unless human beings are taught to use nature with care.

pollution

pollutant

concern

humanity

Ex. 9. Answer the following questions:

1. When did pollution appear? 2. When did pollution increase? 3. Why did pollution increase? 4. In what ways did pollution increase? 5. How can the study of pollution be divided? 6. What sources of air pollution do you know?

7. Where does much dust come from? 8. What are the chief atmospheric gaseous pollutants? 9. What can smog cause?

10. What is the worst type of water pollution? 11. Is there any method of overcoming the effects of oil spills? 12. What do solid wastes include? 13. What steps are taken to pre­vent pollution of the air, water and land? 14. Is it possible to achieve a progress in preventing cities from pollution?

Ex. 10. Find the pairs of synonyms:

rapid, produce, chief, use, quick, help, manufacture, main, application, assistance.

Ex. 11. Learn the following antonyms:

appear—disappear rapidly—slowly increase—decrease soft — hard

Ex. 12. Find in the text the English equvalents of the following words and word combinations:

защита окружающей среды; будущее поколение; сырье; выделять; неполностью; сокращение загрязнения; недо­статок; постоянная забота; улучшать; вредный; разновид­ности; следует отметить; зависеть от.

Ех. 13. Listen to the tape-recorded text and render it in Russian:

These wastes include the unwanted by-products of chem­ical plants as well as of other factories. Their treatment depends upon the nature of the materials. Chemists are familiar with by-products and are working out the ways of disposing of them without polluting public waters.

Organic waste products that cannot be recycled can of­ten be pyrolized, or else burned in such a way that the air is not contaminated appreciably. If the concentration of organiG matter is quite high as in some paper mill wastes,

even material dissolved in water can be burned; there are oxygen torches which operate submerged in water.

Water from a chemical plant which contains traces of organic matter and is about to be returned to a lake or river, may be treated by ozone, a powerful oxidizing agent in aqueous solution.

Ex. 14. Write the translation of the following text;

Lead

Lead is naturally present, in small amounts, in soil, rocks, surface waters, and the atmosphere. Due to its unique properties it has been an element widely useful to human.

This utility has resulted in greatly elevated lead concen­trations in certain ecosystems. Locations where lead is being mined, smelted, and refined, where industries are consuming lead, and in urban-suburban complexes the environmental lead level is greatly elevated. It is widely agreed that a pri­mary source of these latter sites is the combustion of gaso­line containing lead additives. Other important sources include coal combustion, burning or attrition of lead-painted surfaces, and industrial processes.

The atmospheric lead particles are found to be widely distributed over all parts of the earth.

The input of lead, its cycling.within forest ecosystems, its transfer in food chains, its residence in soil received con­siderable research attention.

Grammar: Review of the Absolute Participle Construction and the Subjective Infinitive Construction.

Text: Energy.

kinetic [kaTnetik] primary ['praimari] owe [ou]

assimilate [a'simileit] convert [kon'voT]

Ex. 2. Read and translate the following word combinations: >

chemical and- mechanical energies; kinetic energy; the primary energy; fundamental contribution; type of energy;

vital problem; to make fundamental contribution; thermal dissociation of sulphur trioxide; exothermic catalytic reac­tion; decomposition through gas expansion; thermodynamic inefficiency.

Ex. 3. Read the following words and pay attention to their meaning:

convenient—inconvenient direct—indirect usual—unusual expensive—inexpensive dependent—independent definite—indefinite necessary—unnecessary

Ex. 4. Analyse the following sentences:

1. The products of an exothermic reaction contain less energy than the reactants at the same temperature, this energy being lost to the surroundings. 2. The heat of com­bustion is known to be the energy lost on complete com­bustion of one mole of the substance. 3. Energy is known to be changed from one form to another, but it cannot be created or destroyed. 4, The energy is considered to be heat energy which is transferred to the surroundings. 5. An atomic re­actor getting its energy from a loss in mass during the nu­clear reaction, we consider mass to be a form of energy.

5. There are many forms of energy, kinetic energy being the energy of motion. 7. A ball rolling along a smooth surface can be expected to continue rolling along uniformly unless acted upon by an outside force.

Text. Energy

Energy is the ability of a system to do work.

There are various forms of energy: heat energy, kinetic energy, potential energy, electrical energy, chemical energy and some others.

The primary energy to which all life on earth owes its existence is known to be the energy of the sun. It is assimi- lated by plants and finally transformed to chemical energy which is supplied to man with the food he consumes. Mari' converts the chemical energy to heat energy and mechanical energy, these being the most important types of energy for man. Of course, other forms of energy also make fundament tal contributions, e.g. electrical energy being one of thenb

It should be mentioned that in any transformation of one type of energy into another form, energy cannot be destroyed, but it can be wasted.

A very important problem concerning energy is the stor­age of energy. There are many methods of storing energy, among them being the electrolysis of water.

Another problem to be solved by our researchers is the problem of cost. This problem has been discussed and is being discussed by our engineers and scientists as it is con­sidered to be a vital problem for our national economy.

Electrical energy as a source of heat costs more per unit of energy than does direct heat, because electrical energy proves to be usually produced from heat.

Even when electrical power is produced from the energy of falling water, electricity is usually more expensive per unit of energy than is heat obtained in other ways. As long as energy continues to be wasted, by leaving home and of­fice lights burning unnecessarily the problem is very diffi­cult to solve. People must remember that their life greatly depends on electricity.

The scientists consider our existence on Earth also to depend on the energy received from the sun. It is found to be stored in the foods, in the coal and gas the people burn to keep warm, and in the gasoline to drive machines. That is why much attention is given to the investigation of the sun energy.

Having investigated all phenomena connected with energy, the scientists stated that any form of energy is ca­pable of doing something useful. Therefore energy can be defined as ability to do work. It should be noted that not all forms of energy are easily converted to work, but all forms through suitable transformations can do work.

The word “energy” was derived from the Greek, “en” meaning “in”, and “ergon”, meaning “work”.

ability

primary

owe

assimilate

supply

consume

Ex. 5. Answer the following questions:

1. What is energy? 2. What forms of energy do you know? 3. What is the primary form of energy? 4. What do you know about the energy of the sun? 5. What is a very important problem concerning energy? 6. What methods of storing

energy do you know? 7. What can you say about electrical energy? 8. Where can the energy of the sun be stored? 9. Why can energy be defined as the ability to do work? 10. What does the word “energy” mean?

Ex. 6. Give the synonyms to the following words:

various, finally, to supply, to convert, to require, to produce.

Ex. 7. Give the antonyms to the following words:

ability, important, warm, capable, suitable.

Ex. 8. Translate the following extract into Russian, mind the Absolute Participle Construction:

The first law of thermodynamics states that in a closed system the total amount of energy remains constant, this meaning that the sum of chemical energy C, heat energy U and mechanical energy A will always remain constant in a closed system.

Two factors in this system being known, the third can be computed. According to this law the amount of one kind of energy may change, but this must be compensated by changes in the other two kinds of energy. It being difficult to determine the absolute amount of energy in any system, we must be very attentive indicating the changes which occur.

Ex. 9. Translate the following extract into Russian, mind the Subjective Infinitive Construction:

A certain amount of work proves to be done in a second, in a week or in a month. How fast the work is done is known to be very important. This is stated to be particularly true for machines in this age of automation. They are used to run factories, to drive dynamos for generating our electri­city, to power our automobiles, trains, airplanes, and for many other purposes. The value of a machine was found to depend on how much work it can do per hour or per sec­ond. A diesel engine is known to be able to exert a large force on a long train to accelerate it and move it at a high speed.

Ex. 10. Listen to the tape-recorded text and render it:

What makes a chemical reaction go? This is a question that chemists have asked ever since chemical reactions be­gan to be investigated. At the beginning of the nineteenth century the question was answered by saying that two sub­stances react if they have “a chemical affinity” for each other. This answer, of course, had no real value until some quantitative meaning was given to “a chemical affinity’ and some way was found for measuring or predicting it.

It might be thought that the heat of a reaction is its driv­ing force, and that a reaction will proceed if it evolves heat, and not proceed if it would absorb heat.

This idea, however, is wrong, many reactions proceed even though they absorb heat.

Ex. 11. Translate the following text and discuss it:

It has been found that the reaction of photosynthesis that is carried out by plants is one of the most important of all chemical reactions.

It has not been found possible to carry out the reactior of photosynthesis in the laboratory. Early in the history ol the world, however, nature found a way by developing г special catalyst which is highly effective. This catalyst, called chlorophyll, is a complex substance containing mag­nesium ion. It is the green substance that gives the green color to the leaves of plants. Chlorophyll is green because it absorbs the light in the red-orange region of the spectrum and allows the green light to pass through or to be reflected. The energy of the absorbed light is used for the chemical reaction which is catalyzed by the chlorophyll. This process of photosynthesis is one of the important ways in which man obtains energy from the sun.

Ex. 12. Translate the text In written form using a dictionary:

When one surface rubs over another, the irregularities in the surfaces interlock again. Since the molecules of one surface are continually striking against the molecules of the other surface, they are all set into rapid vibration. The more the surfaces are rubbed together, the faster the mole­cules vibrate and the warmer the substance becomes. Mechan­ical energy is said therefore to be converted to heat energy. A piece of metal resting on a solid support will become warm­er if struck a few blows with a hammer because the hammer imparts some of its energy to the atoms in the metal, increas­ing their linear kinetic energy; it causing the temperature of the metal to rise. If a gas is compressed, its temperature rises. Heat energy produced by friction, compression are all examples of mechanical energy being converted to heat.

Energy and Temperature

The concept of energy is as difficult to define as that of matter.

Energy is involved in doing work, or in heating an ob­ject.

A boulder at the top of a mountain has potential energy. As it rolls down the mountain side, its potential energy is changed into the kinetic energy of its motion. If it were to fall into a lake, and be slowed down by the friction of its motion through water, part of its kinetic energy would be changed by friction into heat, which then would raise the temperature of the boulder and of the water.

In addition, part of its kinetic energy would be trans­ferred to the water.

Another kind of energy is radiant energy, visible light, infrared radiation, X-rays, for example, being radiant ener­gy. They are all closely similar in nature.

When a mixture of gasoline vapor and air is exploded, energy is liberated. This energy is said to be chemical energy.

Grammar: 1. General review of the Infinitive. 2. Review of the ing-forms and Subjunctive Mood. Text: Some Facts about Quantum Mechanics. Lesson 33

intensely [m'tensli] magnetic [maeg'netik] effect [1'fekt] exemplify [ig'zemplifai] diverse [dai'v9:s] unify ['ju:nifai]

nine—nineteenth electricity—electrictical twenty—twent ieth theory — theoretical

intensely active; complete unification; experimental ob­servations; birth of the theory; quantum mechanics; rela­tivity theory; through the concept of; nuclear energy; sig­nificant occurrence.

Ex. 4. Translate the nouns into Russian, mind the suffixes of the noun “-ty”, “-tion”, “-ance”, “-ence”:

unification, observation, prediction, demonstration, rel­ativity, alteration, manifestation, intensity, importance, significance, occurrence, consideration, contribution.

Ex. 5. Translate the sentences into Russian, mind the meaning of the word “much”:

1. It is probable that there were much larger amounts of carbon dioxide in the atmosphere during the Carbonifer­ous Period than at the present time. 2. There is much wat­er in the flask. 3. They worked much as they had to finish their experimental work in due time. 4. How much time will it take you to complete your studies? 5. Silver and copper are said to be the best of all heat conductors: alumi­num appeared to be much better than iron.

Ex. 6. Translate the sentences into Russian, mind the “ing”-forms?

1. The law describing the dependence of the volume of the gas on the pressure is called Boyle’s law. 2, An example of a compound involving a covalent bond between a' halo­gen and a non-metal is chloroform. 3. In this case these pro­cesses are really chemical reactions, involving the formation of new chemical bonds. 4. Elementary nitrogen occurs in nature in the atmosphere, of which it constituting 78% by volume. 5. In the cyanamide process a mixture of lime and coke is heated in an electric furnace, forming calcium acet- ylide. 6. The nitrite ion is a reducing agent, being oxidized to nitrate ion by bromine. 7. The commercial process of manufacturing ammonia from the elements became practi­cable when catalysts were found which caused the reaction to proceed rapidly enough at low temperatures. 8. In in­dustries such as the fermentation industry the control of the pH of the materials being processed is very important.

9. A definite amount of heat is required to convert a crystal into the liquid at the melting point, this being called the heat of fusion. 10. Hg₂Cl₂ is an insoluble white crystalline substance obtained by adding a solution containing chlo­ride ion to a mercurous nitrate solution. 11. The structure having been determined, he attempted to synthesize the

substance. 12. Having determined the weight of the substance they could compare it with another substance, 13. Gases which do not react with the substance may be drived by being bubbled through sulphuric acid. 14. The solubilities of most gases in water are of the order of magnitude of that of oxy­gen, exceptions being those gases which combine chemi­cally with water or which dissociate largely into ions, in­cluding carbon dioxide, for example. 15. Salts such as Na₂S0₄, which result from complete neutralization of an acid by a base, prove to be called normal salts, those containing more acid being called acid salts.

Ex. 7. Translate the sentences into Russian, mind the Infinitives:

1. Many of the substances react readily with water, to form a hydride of one element and a hydroxide of the other.

2. This rule is seen to be followed in many examples. 3. Va­rious well-known procedures have to be used in the synthe­sis of some hydroxy aromatic hydrocarbons. 4. There are many other groups that can replace a hydrogen atom, to form other substances. 5. In softening water by use of cal­cium hydroxide or sodium carbonate enough of the sub­stance is used to cause magnesium ion to be precipitated as magnesium hydroxide and iron as ferrous hydroxide.

6. The effect of probability was found to be described quan­titatively by a new property of substances. 7. To apply a force on one object, we must be able to push it against some other object. 8. Consequently, energy and work have been found to be numerically the same and we may use the same unit of measurement for both. 9. Because oxygen was found to be the only component in air that is paramagnetic the measured paramagnetism of air appears to be directly pro­portional to the amount of oxygen present. 10. These lines were previously thought to be due to atomic hydrogen and to be anomalous because they did not fit the Rydberg for­mula. 11, The identification of the positively charged alpha particles with helium atoms was made by Rutherford by an experiment in which he allowed alpha particles to be shot through a thin metal foil.

Text. Some facts about quantum mechanics

The first half of the nineteenth century was an intensely active period for discovery of electric and magnetic effects, best exemplified by the brilliant work of M. Faraday and

the complete unification of many diverse experimental ob­servations by Maxwell.

Not only did Maxwell’s prediction of the electromagnet­ic nature of light unify the fields of optics and electricity and magnetism, but its subsequent experimental demon­stration by Hertz in 1887 appeared to be a final blow to the old (corpuscular) theory of light.

The early twentieth century saw the birth of the theory of relativity and of quantum mechanics.

The first, due to Einstein alone, completely altered the ideas of space and time, it being an extension of classical physics to the region of high velocities and astronomical distances.

Quantum mechanics on the other hand, was developed over several decades by many scientists and it being an ex­tension of classical physics to subatomic, atomic, and mole­cular sizes and distances.

Fig. 9. The rotation of a single particle about a fixed point.

Relativity theory and quantum theory are known to - constitute what is now called modern physics. Although relativity theory has played a profound role in our everyday life through the concept of the equivalence of mass and energy and its manifestation through nuclear energy, it has not yet played an important role in the field of chemistry.

Quantum mechanics, however, in dealing with the atomic and molecular region has played a very important role in chemistry.

Many scientists were interested in quantum mechanics and worked hard at this problem, one of them being Bohr.

It should be noted that the significant occurrence on the

road to the development of quantum mechanics was Bohr's, theory of the structure of the hydrogen atom.

According to the nuclear model of the atom, the hydro­gen atom can be pictured as a central rather massive nucleus with one electron. Because the nucleus is so much more massive than the electron, we can consider the nucleus to be fixed and the electron to be revolving about it (see Fig. 9).

The force holding the electron in a circular orbit is sup­plied by the coulombic force of attraction between the pro­ton and the electron. It was Bohr’s great contribution to make these assumptions. Bohr’s theory was found to give a very true picture of the hydrogen atom.

the following words and word

Ex. 8. Answer the following questions:

1. What period was active for the discovery of electric and magnetic effects? 2. What did the brilliant work of M. Faraday deal with? 3. What can you say about Maxwell’s prediction? 4. When was the birth of the theory of relativity and of quantum mechanics? 5. What can you say about quantum mechanics? 6. What is called modern physics?

6. What problem did Bohr work at? 8. What do you know about Bohr’s theory? 9. What was Bohr’s contribution to science?

Ex. 9. Translate the following text using a dictionary:

The series of experiments that are known to have revolu­tionized the concepts of physics had to do with the radia­tion given off by material bodies when they are heated.

It is known, for instance, that when the burner of a stove is heated, it first turns dull red and progressively becomes more and more red as the temperature increases. It is also known that as a body is heated even further, the radiation becomes white and even becomes blue as the temperature becomes higher and higher. Thus, we see that there is a con­tinual shift of the color of a heated body from the red through

the white and into the blue as it is heated to a higher and higher temperature. In terms of frequency, the radia­tion emitted appears to go from a lower frequency to a high­er frequency as the temperature increases, because red is in a lower frequency region of the spectrum than is blue.

Ex. 10. Translate the text into Russian and render it:

In 1886 and 1887, while H. Hertz was carrying out the experiments that confirmed Maxwell’s theory of the elec­tromagnetic nature of light, Hertz discovered that ul­traviolet light causes electrons to be emitted from a me­tallic surface. The ejection of electrons from the surface of a metal by radiation is called the photoelectric effect. Two experimental observations of the photoelectric effect are in contrast with the classical wave theory of light. The kinetic energy of the ejected electrons is turned out to be indepen­dent of the intensity of the incident radiation.

According to classical physics, electromagnetic radia­tion is an electric field oscillating perpendicular to its di­rection of propagation, and the intensity of the radiation is proportional to the square of the electric field.

Ex. II. Translate the text into Russian, mind the Infinitives:

Towards the end of the nineteenth century, several ex­periments were found to have been done that were unable to be explained theoretically.

Two of the most famous of these experiments are known to be blackbody radiation and the photoelectric effect. The explanation of these experiments is likely to require a dras­tic break from the theoretical ideas.

M. Planck was able to derive theoretical equations for blackbody radiation. Five years later Einstein explained the photoelectric effect by assuming that electromagnetic radiation itself is quantized and that it consists of a beam of photons. Both Planck and Einstein are assumed to use the same equation to derive their results.

These theories were the first theories to introduce some sort of quantum condition and are the forerunners of mod­ern quantum theory.

Ex. 12. Translate the text, mind the Subjunctive Mood and Adverbial Clauses of Condition:

The Quantum Theory

Any successful theory in the physical sciences might be expected to make accurate predictions.

Given some well-defined experiment, the theory should correctly specify the outcome or should at least assign the correct probabilities to all the possible outcomes.

From this point of view quantum mechanics must be judged highly successful. As the fundamental modern the­ory of atoms, of molecules, of elementary particles, of elec­tromagnetic radiation and of the solid state it supplies methods for calculating the results of experiments.

Apart from experimental confirmation, however, some­thing more could be demanded of a theory. It is expected not only to determine the results of an experiment but also to provide some understanding of the physical events that might be expected to underline the observed results. In other words, the theory should not only give the position, but it is to explain this position.

For example, in quantum mechanics an elementary par­ticle such as an electron might be represented by the mathe­matical expression called a wave function, which often describes the electron as if it were smeared out over a large region of space. This representation is not in conflict with experiment, on the contrary, the wave function yields an accurate estimate of the probability that the electron would be found in any given place. Were electron actually detected, it would be never smeared out but always had a definite position. Hence it is not entirely clear what phys­ical interpretation should be given to the wave function. Ex. 13. Listen to the tape-recorded text and discuss it:

Soviet physicists carry on great theoretical and experi­mental work in the field of physics.

The Kurchatov Nuclear Energy Institute is known to have contributed greatly to nuclear physics.

Another unique physical complex Baksan neutrino ob­servatory of the Institute of Nuclear Research was built in a giant man-made cave in the North Caucasus, it being the largest nuclear physics installation in the world. Now the Party put forward the task of speeding up scientific and technological progress which will rdsult in creating more scientific centres.

Grammar: Review of the Participle II, the Subjunctive Mood and the Infinitive Constructions.

Text: Organic Chemistry, Carbon and Compounds of Carbon.

overwhelming Uouva'welmirj] obvious ['obvias] effort ['efat] diamond ['daiamond] graphite ['graefait] lubricant [4ju;brikantj charcoal ['tjctkoul] amorphous [a'mo:fas] monoxide [mo'mksaid] dioxide [dai'oksaid] poisonous ['poiznosj h(a)emoglobin [,hi:mo(u)- 'gloubin] exhaust [ig'zo:st] potent ['poutontj toxicity [tok'sisiti] ambient ['aembiont] acute [o'kju:t] exposure [iks'pousa] threshold [^/0rej(h)ould] hypothesis [hai'poGisrs] enormous [I'noimas]

Ex. 2. Read fluently the following word combinations:

great technological significance; overwhelming majority; electron diffraction; carbon monoxide; carbonated water; atmospheric contaminants; ambient concentration; carbpn dioxide; forest ecosystems.

Ex. 3. Translate the following sentences into Russian. IWind the Par­ticiple II:

1. As poinied out above heavy water has been carefully studied, new methods referred to earlier having been devel­oped for its isolations. 2. The methods followed in the in­vestigation of some properties of heavy water have been worked out at our research Institute. 3. The first investiga­tor of the chemistry of the complex compounds was the Swiss chemist A. Werner whose concept followed soon by the concepts of other scientists made a great contribution to science of complex compounds. 4. Most rubber referred to in his book goes now into the manufacture. 5. The heat liberated causes a rise in temperature that is indicated on the thermometer. 6. Some of the pressures were measured before the experimental difficulties involved were fully appreciated. 7. Usually the solution is made up somewhat stronger than needed and poured over an excess of crystal­line solvent spoken above. 8. Given the value of x,the veloc­ity of a body can readily be calculated. 9. The amount of material really affected was too small for some purely chem­ical methods. 10. In the systems discussed, all the impor­tant reactions for temperatures involved are stated.

Ex. 4. Translate the sentences into Russian, mind the Subjunctive Mood and Adverbial Clauses of Condition:

1. In general, the chemical reactions that could be used to convert methane into its derivatives could be applied

also to the other hydrocarbons, 2. This same result might have been obtained by adding together in an appropriate way the expressions for the individual molal enthalpies^

2. If the volume of a sample of gas enclosed in the tube were measured at 1 atm, and then mercury were removed,, it would be found that the volume of the sample of gas would become just equal to twice its original value. 4. If more mercury had been removed from the system the volume of the sample of gas would have become just 3 times its orig­inal value. 5. It is necessary that more mercury should be removed from the system, so that the difference in level of mercury would become 507 mm. 6. If there were no order in the way in which atoms of different elements combine to form the molecules and crystals of compounds, it would be necessary for us to memorize one by one the formulas of thousands of substances. 7. The chemical atomic weight defined in this way as the average for the usual isotopic composition of the element would not be very useful unless the isotopic composition were constant. 8. If a substance could be decomposed (that is, if it could be made to undergo reaction in which it is destroyed) to form two or more prod­uct substances, the original substance must be a compound.

TEXT. ORGANIC CHEMISTRY. CARBON AND COMPOUNDS OF CARBON

I

Organic chemistry is an extremely interesting field of natural science and of great technological significance. The overwhelming majority of chemists prove to be engaged in producing organic compounds; several millions being known so far.

In view of their obvious success in the manufacture of synthetic compounds, the chemists are greatly interested in this field of science.

The name organic chemistry, which was originally used to refer to the chemistry of substances that occur in living organisms, is now used for the chemistry of the compounds of carbon. The chemistry of carbon was greatly advanced about a century ago through the development of a general structure theory, this theory being a chemical theory, in­duced from chemical facts.

In recent years it has received added verification through the determination of exact structures of molecules and crys­tals by physical methods, especially X-ray diffraction, elec­tron diffraction, and the analysis of the spectra of sub­stances.

During the first half of the 19th century many organic compounds were found to have been obtained from plants and animals and also to have been made in the laboratory. They were analyzed for their constituent elements, and their properties were carefully studied. Efforts were made to find some correlation between the chemical composition and the properties of the substances.

, Elementary Carbon

Carbon occurs in nature in its elementary state in two allotropic forms namely diamond, this being the hardest substance known, and graphite, a soft, black crystalline substance used as a lubricant. Having investigated all the substances thoroughly the scientists found charcoal, coke, and carbon black to be microcrystalline or amorphous (non­crystalline) forms of carbon.

Carbon burns to form gases: carbon monoxide CO, and carbon dioxide C0₂, the former being produced when there is a deficiency of oxygen or the flame temperature is very high.

This investigation followed by others resulted in new discoveries in the field of carbon. It has been found out that carbon monoxide is a colourless, odourless gas with small solubility in water. It is poisonous, because of its ability to combine with the hemoglobin in the blood in the same way that oxygen does, and thus to prevent the hemo­globin from combining with oxygen in the lungs and carry­ing it to the tissues. It should be noted that the exhaust gas from automobile engines contains some carbon. Never­theless carbon monoxide is a valuable industrial gas, for use as a fuel and as a reducing agent.

Carbon Dioxide

Carbon dioxide is a colourless, odourless gas with a weak­ly acid taste, due to the formation of some carbonic acid when it is dissolved in water. It appears to be about 50% heavier than air. It is easily soluble in water, one liter of water at 0°C dissolving 1,713 ml of the gas under 1 atm pres­sure.

When crystalline carbon dioxide is heated from a very low temperature its vapour pressure reaches 1 atm at 79° at which temperature it vaporizes without melting. If pres­sure were increased to 2.5 atm the crystalline substance would melt to a liquid at 56.6°. Under ordinary pressure, then, the solid substance could be changed directly to a gas.

Carbon dioxide is known to combine with water to form carbonic acid H₂C0₃, it being a weak acid.

If you studied all the properties more thoroughly you would see that carbon dioxide is used for the manufacture of sodium carbonate, sodium hydrogen carbonate, and car­bonated water and for many other uses.

From this short review it’s clear that chemistry of carbon and its compounds is a very important field of chemistry and should be studied carefully.

II

Carbon Pollutants

Carbon monoxide and carbon dioxide are both very im­portant atmospheric contaminants. Human activities are responsible for the introduction of increasing quantities of these gases to the atmosphere. Carbon monoxide is par­ticularly important because of its potent mammalian tox­icity, while carbon dioxide is most significant because of its ability to regulate global temperature. Neither gas is thought to cause direct damage to vegetation at ambient concentrations presently monitored.

Carbon monoxide has not been shown to produce acute effects on plants at concentrations below 100 p.p.m. for exposures from one to three weeks. The threshold of carbon dioxide toxicity to plants is in such excess of ambient con­ditions as to be completely unimportant. The hypothesis that the increasing concentration of carbon dioxide in the atmosphere might result in elevated global temperatures, however, has enormous implications for the health of forest ecosystems.

Remember the following words and word combinations:

overwhelming majority to be engaged so far

correlation valuable

lubricant to reduce

carbon black deficiency to damage

in view of poisonous to be responsi-

recent to prevent ble for

Ex. 5. Answer the following questions:

1. What is organic chemistry? 2. Why are the scientists interested in the field of organic chemistry? 3. What does the name organic chemistry refer to? 4. When was the chem­istry of carbon advanced? 5. What phenomenon was found during the first half of the 19th century? 6. Where does carbon occur? 7. In what form does carbon occur in nature?

6. What gases does carbon form during its burning? 9. What properties of carbon monoxide do you know? 10. What pro­perties of carbon dioxide do you know? 11. What does car­bon dioxide form combining with water? 12. What are very important atmospheric contaminants?

Ex. 6. Retell the text according to the following plan:

1. Organic chemistry. fi 2. The chemistry of carbon.

3. Elementary carbon.

• 4. The properties of carbon.

_v. 5. Carbon monoxide.

. 6. Carbon dioxide.

5. Carbon pollutants.

Ex. 7. Translate the following text into Russian;

The atmosphere contains about 0.03% carbon dioxide. This figure can’t be fully relied on. Additional carbon dioxide is being poured into the atmosphere all of the time. All animals have been found to exhale carbon dioxide, it having been produced by the oxidation of carbon compounds in their tissues. Carbon dioxide is also produced by the burning of wood and coal and the slow decay of plant and animal remains.

This is a great threat. This problem has been much spoken of by many scientists. Carbon dioxide is taken from the air by the plants, and it is broken down into carbon and free oxygen, it being liberated into the air.

Some of the plants are burnt or are oxidized during the process of decay. The decay is followed by the return of carbon to the atmosphere as carbon dioxide.

Ex. 8. Listen to the tape-recorded text and discuss it:

There are two crystalline forms of carbon, graphite and diamond. These two types of crystals have different struc­tures, and their properties being mostly different from each other. However, diamond and graphite are alike in that they both are refractory that is rfonmelting at high temper­atures and are difficult to burn in air. Slow oxidation of graphite in air does not start until about 450^cC, and that of diamond at about 800°C.

It has already been said that the common crystalline form of carbon is graphite. Most graphite is made by heat­ing petroleum coke in the absence of air in an electric fur­nace to a temperature of about 2700°C.

A graphite crystal consists of layers. The uses of graphite depend chiefly on its lubricating properties, its resistance to oxidation in air. Graphite is used as a lubricant in the form of both dry powder and suspensions in liquids.

Ex. 9. Listen to the tape-recorded text and retell it:

Diamond

Diamond is the hardest known substance. Most diamonds are obtained from natural sources, the chief source being the diamond mines.

Diamond can now be produced in the laboratory. The first synthetic diamonds are said to be made in 1955. They were small. The commercially produced diamonds are still small. They are known under the name “industrial diamonds”. They are used as polishing powder. The diamond grit ap­pears to do all the cutting.

Ex. 10. Translate the text in written form using a dictionary:

The gases and vapours from the coke oven are cooled to ¹ condense out of the most liquid products and the tar. The last of the tar is usually removed by electrostatic precipi- ! tation. The liquid products appear to include an aqueous phase containing some ammonia and an organic phase which contains benzene and a variety of higher aromatic coal­tar-hydrocarbons, the aqueous and organic phases being separated. The mixture of organic products is distilled into a number of crude fractions. The crude fractions are redis­tilled and purified to obtain benzene, toluene, phenol and other chemicals.

Ex. 11. Read the text and render it:

Carbon and hydrogen are the principal constituents of the solid fuels coal and wood. Coal has been formed in na­ture by the slow decomposition of vegetable matter, in the presence of water and absence of air. Most of it was formed

during the Carboniferous Period of geologic time, about 250 million years ago. Coal consists of free carbon mixed with various carbon compounds and some mineral matter. Anthracite coal (hard coal) contains only a small amount of volatile matter, and burns with a nearly colorless flame; bituminous coal (soft coal) contains much volatile matter, and burns with a smoky flame.

Bituminous coal can be converted into coke by heating without access of air. When the heating is carried out in a by-product coke oven, many substances distill out, includ­ing gas for fuel, ammonia, and a complex mixture of liquid and solid organic compounds. The solid material remaining in the ovens, consisting mainly of carbon, is called coke. It burns with a nearly colorless flame, and is used in great amounts in metallurgical processes.

Petroleum is a very important liquid fuel. It is a com­plex mixture of compounds of carbon and hydrogen.

The gas obtained from a coke furnace (coal gas) consists of hydrogen (about 50%), methane, CH₄ (30%), carbon mon­oxide (10%), and minor components. This coal gas was the original illuminating gas.

Natural gas, from gas wells and oil wells, consists largely of methane.

Ex. 12. Read the text; give the main idea in two or three sentences:

Every year there are changes in climate in different parts of the world. Some of these changes are due to natural causes. However, some climatic changes are caused by air pollution and these changes may increase. One kind of pol­lution results from burning oil and coal in transport and in factories.

If the pollution affects the level of carbon dioxide in the atmosphere, the results are likely to be serious. Carbon dioxide constitutes only a small part of the atmosphere. But it has an important function in maintaining the bal­ance between radiation from the sun entering the atmosphere and radiation leaving the Earth. Some of the radiation is absorbed by the Earth and some is radiated back into the atmosphere. The carbon dioxide in the atmosphere prevents some of the radiation from leaving the atmosphere. Thus, the heat remains in the atmosphere and carbon dioxide helps to prevent the temperature of the Earth from falling.

If the proportion of carbon dioxide in the atmosphere is increased as a result of air pollution, the temperature of the atmosphere may rise. This might eventually cause the

№

ice in the north and the south poles to melt. If this happened, the sea level would rise and parts of the Earth would be flooded. The likelihood of this happening is remote, but the possibility exists.

There is also a fairly strong possibility that the dust level in the atmosphere will rise as a result of industrial pollution. This dust pollution will reflect sunlight back into space. If this happens, less sunlight will reach the Earth and the temperature will fall.

Gramma r: General Review. Text: Zinc.

whilst [wailst] commercial [кэ'тэ:/э1] separate ['separit] phase [feiz]

immediately [i'mi:djotli] furnace ['fo:ms] occasionally [o'keisnoli] escape [is'keip]

Ex. 2. Read the following word combinations;

on a commercial scale; as early as 200 B.C.; whilst it is oxidized; insufficient to have any commercial impact; when unalloyed; the creep resistance; atmospheric corro­sion; the electro-negative character; partly ionic and partly covalent.

Ex. 3. Pay attention to the word combinations in bold type, translate them into Russian:

1. As early as in 19th century .... 2. This experiment is as important as .... 3. As far as this report is concerned .... 4. As far back as in 1947 .... 5. As late as in the 18th century occurs .... 6. As long as this reaction occurs . . . . 7. As soon as he comes ....

Ex. 4. Translate the following word combinations, mind the Partici­ples II:

the method involved was; the experiment spoken of is; the lecture followed by the experiment took place; the data

referred to must be; the report presented involved some data; the figures summed up resulted in; the book trans­lated consisted of 2 parts; the work done helped greatly; the ore found contained; the solution used is to be heated!

Ex. 5. Translate the following sentences, mind the Infinitives:

1. The copper to be used must be pure. 2. The metal is to be used in our experiment. 3. To use this solution we have to heat it. 4. To use these figures is to complete this work. 5. The method seems to be useful in this work. 6. The work done proves to be of great importance. 7. They found this substance to melt at a low temperature. 8. The appli­cation of zinc is known to be important in heavy industry.

6. Zinc is known to be a silvery white metal. 10. This metal appears to be readily dissolved by most mineral acids.

TEXT. ZINC I

The production of zinc occurred much later than that of the other common metals. Whilst copper was smelted from its ores probably about 5000 B.C., lead was produced about 4000 B.C. and iron about 2000 B.C., zinc does not seem to have been available on a commercial scale until the four­teenth century.

As a metal zinc was certainly known before this time. Brass, an alloy of zinc and copper, was produced by the Ro­mans as early as 200 B.C., but the method they used in- vloved the heating together in crucibles of copper, zinc oxide and carbon. The zinc formed by reduction of the oxide was absorbed immediately in the copper and was not produced as a separate phase.

Most lead ores contain zinc, and during smelting, a pro­portion of the zinc oxide present is reduced and forms zinc vapour, and whilst most of this is oxidized immediately in the upper levels of the furnace, occasionally some escapes and condenses as metal in the flues, and can be recovered from the fume scraped from the walls. Only very small amounts could have been collected in this way, insufficient to have any commercial impact, but enough to show the exist­ence of the metal, to enable its characteristics to be deter­mined, and possibly to account for the few zinc objects which archaeologists have found dating from B.C.

Zinc is a silvery white metal with a relatively low melt­ing point (419.5^CC) and boiling point (907°C). When unal­loyed its strength and hardness is greater than that of tin or lead, but appreciably less than that of aluminium or cop­per and it cannot be used in stressed applications. Except when very pure, zinc is brittle at ordinary temperatures but malleable above 100°C and can then be readily rolled. When alloyed with 4 per cent aluminium its strength and hardness is increased considerably. Small additions of cop­per and titanium appreciably improve the creep resistance of rolled sheet and the use of this material is growing. With additions of 20-22 per cent aluminium, superplasticity can be developed, the alloys produced flowing readily at tem­peratures of 220°C under vacuum.

One of the most useful characteristics of zinc is its re­sistance to atmospheric corrosion, one of its main appli­cations thus being for the protection of steelwork. The elec­tro-negative character of zinc also leads to its use in consid­erable quantities in dry batteries.

Zinc, cadmium and mercury constitute Group I IB of the periodic table.

Zinc is divalent only and can give up the two outer elec­trons to form an electrovalent compound, for example, zinc carbonate ZnC0₃. It may also share those electrons as in zinc chloride ZnCU, in which the bonds are partly ionic and partly covalent.

Remember the following words:

brass

reduction

level

occasionally to escape

Ex. 6. Answer the following questions:

1. When did the production of zinc occur? 2. When was lead produced? 3. What is brass? 4. What characteristics of zinc do you know? 5. What chemical properties of zinc do you know?

Ex. 7. Translate the text using a dictionary:

Ore Concentration

The character of zinc ores is almost invariably highly complex and in addition to containing considerable quan-

tities of gangue material, almost always they contain other metals which must be recovered in a pure form as possible. It is particularly important that high grade concentrates should be obtained, since for all the processes for production in use, the costs of production rise steeply with decreasing grade of concentrates treated, and therefore the maximum possible degree of separation and purification in the con­centrating plant is always demanded. It is fortunate that the flotation process has been developed to a high pitch of perfection and good grade concentrates can now be obtained from most sulphide ore bodies. As a result the flotation process has now almost entirely replaced the older specific gravity based on methods of concentration.

No two ore bodies are identical; they differ in mineral- ogical constitution and chemical composition. Even from the same mine considerable variations in the composition of the ore may occur from day to day.

Ex. 8. Read the text and render it:

As with most metals, the zinc industry relies on the for­tunate fact that at certain spots on the earth's surface a high degree of concentration of the metal has taken place to form workable ore deposits. The flotation process permits the minerals in these ore bodies to be still further concen­trated until they are then worth treating by the electrolytic or smelting processes now available.

With present techniques the dependence of the zinc in­dustry on the discovery and exploitation of these ore bodies is complete. Their occurrence in the earth's surface is al­most certainly limited and their availability in sufficient numbers in the future must be a matter of some concern since the demand for zinc has been growing at a consid­erable rate.

Ex. 9. Read the text, analyse the grammar constructions:

Brass

The addition of zinc to copper to form brass is the oldest and one of the most important applications of zinc. The art of producing bronze by alloying copper with tin was devel­oped relatively early and was one of primitive man’s great­est technological advances, but, due to the difficulties in­herent in the metallurgy of zinc, brasses do not seem to have been produced until the first or second century B.C., when the cementation process was practised in India and

China, and also in Europe by the Romans. A mixture of zinc oxide (as calcined calamine) and charcoal was placed in a crucible and covered by a layer of pieces of copper. The crucible was heated to 1000^CC, when the zinc oxide was reduced and formed zinc vapour, which dissolved in and was retained by the copper. As the zinc content of the cop­per rose to approximately 30 per cent, the alloy began to melt and ran down to the bottom of the crucible, and at the end of the reaction was cast into moulds—usually made of stone slabs—and later hammered into the shapes required. The process did not involve the separation of zinc as metal.

The method was the main source of brass production for many centuries. It was not capable of producing alloy con­taining more than 30 per cent zinc, and, due to losses which must have been difficult to avoid, considerable skill must have been required to reach this figure.

When methods for producing zinc were developed in India and China in the thirteenth and fourteenth centuries A.D., and the metal became generally available, some brass was made by directly alloying the two metals. This method was more controllable and enabled alloys with a higher zinc content than 30 per cent to be made if required, but the cementation process was presumably cheaper and its use did not die out for many years.

The brasses constitute an important series of alloys, since by varying the composition and heat treatment, a wide range of mechanical properties can be produced with valuable characteristic and excellent corrosion resistance. They form one of the three major outlets for zinc metal but as copper is the major constituent of the commercial brasses they are described in detail in the handbook on copper in this series.

Ex. 10. Read the text and discuss it:

As would be expected from its relatively low melting point, zinc itself, and the alloys of which it forms the main constituent, have only mediocre physical properties, and cannot be used for highly stressed applications; neverthe­less, the zinc-aluminium alloys, with their good ability to be cast, fill a gap between plastics and the stronger but higher melting point aluminium alloys, the brasses and nickel-containing alloys, and one of the main outlets for zinc is in the diecasting industry.

Another major use for zinc is the series of alloys with copper to form the brasses and nickel silvers. By varying

the zinc content from 15 per cent to 40 per cent alloys with a wide range of strength and ductility can be produced.

An important outlet for the metal itself is in rolled form, zinc sheet being used to a considerable extent for roofing and cladding. It is handicapped by a low resistance to creep, although this can be overcome to some extent by small ad­ditions of copper and titanium.

Ex. П. Listen to the tape-recorded text and render it:

The Protection of Steel Work by Zinc

Zinc coatings are one of the best methods for the protec­tion of steelwork against corrosion. There are two reasons for this, the first being that zinc is itself resistant to normal atmospheric corrosion—instances have been recorded where zinc roofing sheet has given service for over 100 years. In most atmospheric conditions the rate of attack on zinc is only 3-10 per cent that on steel, and this is due mainly to the grey impermeable film which forms over the surface of the metal exposed to air. This resists further attack, al­though in industrial atmospheres containing sulphur dioxide the film is less stable because it consists largely of basic zinc carbonate which reacts with the sulphurous acid. Thus, a coating of metallic zinc on steelwork forms a durable bar­rier affording considerable protection under normal condi­tions. The second reason arises from the fact that zinc is considerably more electronegative than iron, and when the two metals are in contact in an electrolyte, zinc tends to dissolve, leaving the iron unattacked.

Exercises for translating the passive voice

Ex. 1. 1. There are a number of coloured substances, in a natural fibre that are changed to colourless products by reaction with oxygen. Many of these substances are not affected by atmospheric oxygen. 2. Complete precipitation is often ensured by the use of the common ion effect. 3. A few of the uses of aluminium have already been referred to in the article published this month. 4. Ions, such as the hydro- nium ions, which are made up of several atoms held together by covalence, are known as radicals. 5. An unsaturated com­pound is defined as one in which the maximum valency is not exerted by all the component atoms. 6. Cellulose ace­tate is unaffected by weak acids, oils and most solvents.

7. Since X-ray patterns for some amorphous substances are similar to those of fluid liquids, they are looked upon as liquids which have high viscosities, and are often referred to as supercooled liquids. 8. The preparation of sodium chro­mate from chromate ores has already been spoken of. 9. The discovery of manganese is usually credited to Cahn. 10. This question can’t be answered at once. It should be thoroughly studied. 11. The heating of the solution was followed by a sudden cooling, which resulted in forming of a new product.

12. Oxidation has been defined as the losing of electrons.

13. The same procedure is followed in deriving the formula of a compound containing more than two elements. 14. Gold is slowly attacked by fused nitrates and alkali-metal hy­droxides. 15. Glass and silica are not attacked by sulphuric acid of any strength.

The modal verbs and their equivalents

Ex. 2. 1. If the substance for which the formula is to be derived is both non-volatile and insoluble, its molecular weight is always unknown. 2. The most striking contrasts

m

between organic and inorganic chemistry is to be found in the instantaneous character of most inorganic reactions. 3. Any material whose properties are to be studied must first be suitably purified. 4. The emulsion has to be sufficient­ly robust to withstand pigmentation. 5. If positive ions of a given element are to be deposited as the free element on a cathode, it is evident that the ions must be converted back into atoms. 6. Theoretically any element should be able to force any element below it in the series. 7. The dispersing action of water on an ionic solid may be ex­plained in terms of the polar nature of its molecules. 8. This work can’t be carried on in this laboratory. 9. We must make a brief excursion into the realm of geology if we are to get any clear understanding of the nature of the minerals.

10. They had to graduate from the Institute last year. 11. When liquid air is allowed to evaporate, different compounds pre­dominate in the fractions obtained at different temperatures.

12. By studying matter in bulk, physicists have been able to draw conclusions concerning the size and weights of the atoms and molecules. 13. From all that has been said, it might be imagined that structural formulas were the result of pure speculation. 14. A complex ion is to be regarded as a chem­ical entity with its own properties. 15. It is to be remem­bered that no animal can live without oxygen. 16. You should be very careful if you are to carry out this experi­ment in our laboratory. 17. The results reported have to be examined thoroughly. 18. The electron spectrometer used for this investigation is to be of a new type. 19. The surface of the metal has to be well cleaned before resins are applied, and at least some hours must be allowed for the resin to cure. 20. A substance may be crystalline and yet show no external regularity. 21. Once the pressure at which the distillation is to be conducted is established, the number of theoretical or equilibrium stages is determined.

THE PARTICIPLES

Ex. 3. 1. A consideration of the equilibria involved in a solution of potassium cyanide illustrates the relationships upon which the degree of hydrolysis depends. 2. The increased concentration of the ions of water increases the effects caused by these ions. 3. The change in solubility resulting from the rise in temperature causes the completion of some hydrolytic reactions which are normally incomplete. 4. A very porous product used as a heat insulator is produced

by preparing a mixture of this substance with asbestos.

5. There are several different types of alloys, some being homogeneous and others heterogeneous. 6. Many of the metallic products, used extensively, are not single metals but alloys. 7. Salt can,be obtained from salt mines, sea water. The impure salt thus obtained may be purified by recrystallization. 8. A solution containing no excess of either the acid or the basic hydroxide is known as a neutral solu­tion. 9. Equations are known to show the proportions in which the substances concerned react, consequently, the quantity of one of the substances involved establishes the quantities of all of the others. 10. A salt is a compound re­sulting from the replacement of the hydrogen of an acid by a metal or a metallic radical. 11. The reaction of non-metal oxides with basic hydroxides are closely related to the two types of reactions of acidic substances with basic substances already considered. 12. The partial pressure exerted by each gas in the mixture depended on the per cent of its molecules,

1. e., upon the relative value of the molecular concentration of the gas. 13. The gaseous molecules, formed by the evapo­ration of a liquid, constitute its vapour. 14. When dissolved in cold water, the acid reacts very slowly. 15. Ultramarine is stable to bases, but decomposes to yield hydrogen sulfide when treated with acids. 16. The hydrogen atom, having its valence electrons in the first level, is smaller in diameter than is the sodium atom. 17. Aluminium oxide like magne­sium oxide decreases greatly in volume if heated in an elec­tric furnace. 18. The temperature remaining constant, the volume of a given mass of a gas is inversely proportional to the pressure to which it is subjected. 19. The barometer _ commonly employed in the laboratory consists of a V-tube closed and evacuated at one end. 20. A number of investi­gations have been carried out using a procedure in which no absolute values need be known, all the results being referred to an arbitrary chosen substance, such as benzoic acid. 21. The steam expanding, its volume increases. 22. The experiment followed by the discussion was carried out by our young research workers. 23. Carbon dioxide, being highly exothermal in its formation, is quite stable with respect to heat. 24. Other conditions being equal, iron heats up faster than aluminium. 25. Having absorbed twice as much heat, the aluminium when it is cooled can also give up twice as much heat as iron. 26. The isolation of radium followed by many important investigations resulted in many new discoveries. 27. The dilute solution of hydrogen peroxide

decomposes slowly liberating oxygen gas, it decomposing more rapidly when heated, or when exposed to sunlight. 28. Dilute solutions are stable if kept in a dark and cool place. 29. Electroplating was invented in Russia, the in­ventor being the Russian scientist Jacobi. 30. The principal materials affected by magnetism are iron and steel. 31. The professor much spoken about is to deliver a lecture in our Institute next month. 32. The type of spectrum emitted depended considerably on the source used. 33. The values obtained are to be thoroughly examined.

The gerund

Ex. 4. 1. Insoluble compounds are removed by allowing them to settle or by filtering. 2. Alloys are usually prepared by melting metals together and allowing the melt to cool. 3. By cooling the solution a temperature is reached at which the solid pure ice and the liquid solution have the same vapour pressure. 4. After having made a number of exper­iments, the Soviet scientists and engineers succeeded in creating an automatic interplanetary station. 5. We have learned of his having finished a number of new laboratory experiments. 6. Freon is used in some refrigerating machines, it has the advantage of being nontoxic and noninflammable.

7. Hydrogen chloride is usually prepared by heating a mix­ture of concentrated sulphuric acid and the appropriate salt. 8. A catalyst is a substance which alters the speed of a reaction without itself being consumed in the reaction.

9. Iron is the most useful of metals, partly because of its extreme abundance, but largely because of the ease with which its properties may be altered by adding small amounts of other elements. 10. Water gas is obtained mainly by pass­ing steam over coke. 11. Ethylene is a material which is widely available in refining gases. 12. After having reached the boiling point, the temperature of water could not be increased any more in spite of our adding more heat. 13. Add­ing heat to a piece of ice or increasing the pressure upon it means to change it to water. 14. The cooling of a gas which occurs when it expands without doing external work is known as the Joule-Thompson effect. 15. Some metals are remarkable for being very light. 16. Your having carried out this work under this professor helped you greatly in your research work. 17. Physical properties are those that may be expressed without considering the possibility of transforming the given

material into materials of other kinds. 18. The capacity material for being dissolved in water or in some other vent is also commonly listed as a physical property. 19. 1 has the chemical property of being transformed into ol materials.

THE SUBJUNCTIVE MOOD AND ADVERBIAL CLAUSES OF CONDITION

Ex. 5. 1. This effect would be expected to produce opposite result to that discussed in the preceding paragra

2. The existence of minute particles in the atoms of the ments is now considered to be fully established. Five par les, which might serve as units, have been described. 3 the solution were treated with a weak acid or with a \ dilute solution of one of the stronger acids, weakly ioni hypochlorous acid would be formed. 4. Precipitation wc occur until the concentrations of the ions in solution i been reduced to such a point that the product of their c centrations would not exceed 1.69X10^-10. 5. Since the dium has a much greater tendency than does hydrogen loose its one valence electron, it is to be expected that ionic hydroxide of sodium would be formed. 6. Neither w acids nor weak bases would react with aluminium hydro* to produce salts. 7. Most of the reactions of inorganic cht istry are those which occur between solutions of eleci lytes, so it is highly important that the chemical behavi of such solutions should be considered. 8. If we attemp to prepare hydrogen bromide in a test-tube with a cone trated sulphuric acid, the result would not be satisfactc

9. Were the sulphur melted, a little above the boiling pc of water, and allowed to cool, it would form long monocli needles. 10. The total surface of a cube with 1 cm edge: 6 sq cm, if this cube were cut in half along each of its th dimensions, there would be eight cubes. 11. One might why engineers prefer to supply us with a.c. rather than c We could easily understand this if we remembered that c rent flows first in one direction. 12. It is necessary that t source of heat should be removed. 13. The scientists sugg< ed that this substance should be examined under the m powerful microscope. 14. Whenever we have to deal w a substance that is only slightly ionized, the general res of the reaction may be obtained by treating the substa: as if it were not ionized at all. 15. He insists that we shoi

take part in this research work. Had we been told earlier, we should have agreed, but now we can’t. 16. The container should be thoroughly cleaned lest grease should prevent the reaction. 17. As might be predicted from its position in the periodic table, fluorine is the most active of the electron- gainers. 18. Since carbonic acid is so weak, one would ex­pect the existence of only the carbonates and bicarbonates. 19. Had water been added to the mixture, more alcohol and acid would have been formed. 20. Water might possibly be considered a polybasic acid as a consequence of having two hydrogen atoms in its molecule. 21. To prevent refor­mation of these layers it would be necessary to decrease the surface tension of one, or of both liquids. 22. Phosphoric acid behaves in certain respects as if it were a mixture of three different acids of different degrees of activity.

The infinitive

Ex. 6. 1. M. V. Lomonosov was the first to found Rus­sian materialistic philosophy in the middle of the 18th cen­tury. 2. Water that has been very carefully purified by repeat­ed distillations proves to be a rather good insulator. 3. To make a precipitation as complete as possible, it is necessary to add a slight excess of one of the ions concerned in the formation of the precipitate. 4. We found water and water vapour to be in equilibrium at constant temperature and pressure when the thermodynamic potential of unit mass of the water is equal to that of unit mass of vapour. 5. For nearly a century after Dalton formulated the atomic theory, atoms were generally assumed to be the indivisible parti­cles of the elementary substances. 6. The particles in the positive rays are assumed to be formed by removal of one or more electrons from the atoms. 7. The lightest of the pos­itive ray particles proves to be formed when hydrogen is the residual gas in the tube. This particle is considered to be a second fundamental unit of matter. 8. The first step in the experimental determination of the atomic weight of an element by this method is to find the weight of one mole of several of its compounds. The second step is to analyse the compounds. 9. Some metals, active enough to combine extensively with carbon, may be produced by the reduction of the oxides with aluminium. 10. Chlorine reacts with cal­cium hydroxide to form a mixed salt with the two negative ions. 11. In a number of instances some ions are hydrolyzed to give acidic solution. 12. Atoms are too small to be seen even under a powerful microscope. 13. The metal hydro­xides react with acids and with oxides of non-metals to form water and a class of compounds known as salts. 14. Carbon dioxide reacts with sodium hydroxide to yield water and sodium carbonate. 15. It was observed in 1930 that the bom­bardment of beryllium by alpha-particles from polonium gives rise to a very energetic type of radiation, this radiation was thought to consist of gamma-rays, but the energy re­lationships were found to disagree with this assumption. 16. In 1911, E. Rutherford proposed all of the positive elec­tricity and nearly all of the mass of the atom to be concen­trated in a very small nucleus, with enough electrons out­side of this nucleus to equal the positive charge. 17. A large proportion of the particles in an alpha-ray beam proves to pass through a metal film placed in its path and fall upon a screen without significant change in direction, while oth­ers show large deflections. Consequently, rays are scattered over a wide area, the deflections are too great to be caused by single electron or proton. 18. Some years ago, it was discovered that' anhydrous aluminium chloride added to motor oil caused a sediment of dark material to form. 19. Alu­minium is the third element of the third period and the most abundant of the metals to be found in the earth’s crust. 20. When concentrated solutions of substances which exist as ionic crystals are diluted, the degree of ionization appears to increase. 21. The first man to study thoroughly the electrolytic properties of solutions was M. Faraday. 22. Chem­ists have long believed chemical reactions to be of an elec­trical nature. 23. The conditions to be observed are well illustrated in this chapter. 24. The treatment to be given any sample of water, in order to fit it for industrial use, will, of course, depend on the kind of impurities to be removed and should be based upon a careful chemical analysis. 25. To be useful as an ore, an iron mineral must contain at least 30 to 40 per cent of iron. 26. To improve the quality of pig- iron it is to be purified by melting in a furnace. 27. Robert Boyle was the first investigator to study quantitatively the relationship which exists between the volume of a gas and the external pressure which is exerted upon it. 28. We have noted that one of the three chief problems of chemistry is to discover the means and conditions for changing any given kind of matter into matter of other kinds, that is, into new material.

Ex. 7. 1. The formulas of elements are derived in the same way as those of compounds. 2. It is important to re­member that in terms of the ionic theory a neutral solution is one containing H⁺ and OH“ ions in the same concen­tration as in water. 3. The solubility of helium is much less than that of nitrogen. 4. The changes that take place during the freezing of a liquid are opposite to those that take place during the melting of the solid. 5. The strong odour charac­teristic of burning sulphur is that of sulphur dioxide. 6. To understand this matter thoroughly, one must have first a knowledge of reaction rates. 7. That ions do migrate to the pole of unlike charge can be shown by a very simple exper­iment. 8. The volume to be occupied by a given mass of any substance is much greater in the state of vapour than in that of a liquid. 9. Substances that may be prepared from, or that may be resolved into elementary substance are called compound substances. 10. That the sun is a star is a very important fact. 11. A concentrated solution is one that con­tains a relatively large amount of solute in a given volume of solution. 12. Note, that a saturated solution is not one that contains as much of the dissolved substance as it can be made to dissolve. 13. One gram of water will dissolve almost 5 g. of zinc chloride but only about a millionth of a gram of silver chloride at room temperature. 14. Equa­tions that do not involve oxidation and reduction as well as many that do are very easy to balance. 15. Oxidation and reduction have much broader meanings than those indi­cated by the previous definition. 16. Nearly all the elements that have been shown to consist of mixtures of isotopes are those the atomic weights of which are very different from whole numbers. 17. These experimental methods were simi­lar to those known before. 18. When the currents to be de­tected are very small, one should use a galvanometer. 19. Ob­servation leads one to note continual changes in the ma­terial environment. 20. The small crystals dissolve and the larger ones increase in size when such a suspension is allowed to stand. 21. Chlorine is so active chemically that it is never found free in nature. 22. The terms “oxidizing agent” and “reducing agent” are purely relative ones. 23. That the at­mosphere is a mixture and not a chemical compound at all, is proved by the fact that it varies somewhat in its compo­sition from place to place and from time to time. 24. On

theoretical grounds one would expect the minimum fre­quency for ionization to be connected with the ionization potential.

Whether

Ex. 8. 1. The same products result from the complete reaction of oxygen with a substance whether the reaction takes place slowly, or rapidly. 2. Whether H₂0₂ acts as an oxidizing or reducing agent depends not only on the specific nature of the substance with which it is placed in contact.

2. It is impossible to say whether water above its critical temperature should be considered as a liquid of very low density, or as a vapour of exceedingly high density. 4, Wheth­er a solution is saturated, supersaturated, or unsaturated may be determined by noting what happens when an addi­tional crystal of the given substance is thrown into it. 5. Wheth­er obtained from sea water, from salt lakes, or produced in the laboratory, salt contains two elements in the same ratio. 6. If we wish to know whether many moles correspond to a given volume of a substance we may use either of the two methods. 7. Whether a substance will dissolve and form a solution is based upon three things. 8. The groups, whether molecules or ions, which are attached by bonds to the cen­tral atom in a complex ion are known as ligands.

FOR, SINCE

Ex. 9. 1. For a long time this substance was considered to be stable. 2. If the two liquids are very different in den­sity, this method may give only very rough results, for a very considerable increase or decrease in volume may take place when the two are mixed. 3. For the composition of solutions is not definite, the concentration of the solute may be varied. 4. They have been working for ten days, but still there is much to be done. 5. The chemical symbol for water is known to be H₂0, H standing for hydrogen, О for oxygen. 6. Sulphur hexafluoride is of great theoretical interest for its properties illustrate how inert it may be.

7. For the first time in history the Soviet man Y. Gagarin flew into the space. 8. For a long time this problem couldn't be solved. 9. In fact, the higher the temperature we employ, the worse are the results we get, for the change is reversible and the reverse reaction is the one that is favoured most by the application of more heat. 10. If the substance for which the formula is to be derived is both non-volatile and insoluble, its molecular weight is unknown. 11. They haven’t been to this plant since they moved to another town.

REVISION GRAMMAR EXERCISES (for home-work)

THE PASSIVE VOICE

1. The experimental results will be referred to in the article which is to be published in our local journal. 2. Enough has already been written about this new discovery. 3. After a long discussion the decision was arrived at. 4. La­tely much attention has been given to the artificial fibres which can be produced from oil. 5. All his remarks about this new work have been taken into account and particular consideration is .given to the experimental part. 6. The con­ference was attended by many foreign scientists working in the field of nuclear physics. 7. They have been given the results of the tests carried out in our laboratory. 8. The agreement between these two relations can be reached if you examine the data thoroughly. 9. Once the distribution of gas velocities has been calculated, the final step is to determine the nature and extent of the separation of uranium isotopes in the gas. 10. The composition of the product is profoundly affected by addition of chlorine and hydrogen chloride. 11. The rate of reduction of the amount of oxygen was affected by the oxidizing conditions. 12. Any neutrons and protons left over after the formation of the maximum number of alpha-particles are looked upon simply as being present in the nucleus. 13. This technique has been followed in our research work and it proved to be very reliable. 14. They were offered a very interesting work which could re­sult in a new discovery. 15. The method of preparation of oxygen by the decomposition of potassium chlorate was described in chapter 5. 16. Special mention must be made of the extensive research now being conducted in biochem­istry. 17. The electrons in any one energy level were spoken of as if they all possessed exactly the same quantity of energy. 18. In general the oxidation number is thought of as representing the net electrical charge on the atom.

19. These calculations can be fully relied on as they have been checked repeatedly. 20. The coefficient of heat transfer in any vaporator is considerably affected by the magnitude of the temperature drop, the rate of circulation and some other factors. 21. For many years it has been known that some substitution reactions of complex ions are hastened by light. 22. The reactions were followed by titration with a standard base. Methyl Red—Metylene Blue was used as indicator. 23. Platinum is attacked only slowly by fluorine. Copper and steel can be used as containers for the gas; they are attacked by it, but become coated with a thin layer of copper fluoride or iron fluoride which then protects them against further attack.

The participles

1. This behaviour can be understood in the light of the formation reaction in which the electric fields of completed molecules or ions interact with adjacent ions or molecules, thus forming compounds of a higher order. 2. Based on the laws of conservation we can formulate chemical equations with a somewhat greater measure of justification. 3. Depend­ing on their chemical compositions, solvents are divided into polar and non-polar solvents, and intermediary types, non-polar solvents being organic hydrocarbons. 4. The pres­sure exerted on the walls of a container by a gas is entirely due to collisions that take place between the moving mole­cules and the walls. 5. All of the carbonions described are powerful nucleophiles, they being used for the reactions given below. 6. When considering the stability of equili­brium, we should start from some definition and, using this, investigate the given system, the investigation might pro­ceed in two ways. 7. Some of the compounds involved have not been reported previously, additional data being reported in the appendix referred to in this report. 8. The results obtained for the analyses of a group of synthetic mixtures were as satisfactory as those obtained from other group methods. 9. All the processes described above take place more or less simultaneously, the hydrolysis of acetylchlo- rine resulting from a combined action of all the functional groups. 10. This indicates that the carbon dioxide evolved on heating results solely from the decomposition of carboxyl groups referred to earlier, one carboxyl group giving one mole of carbon dioxide. 11. The temperature remaining constant, the volume of a given mass of a gas is inversely proportional to the pressure to which it is subjected. 12. Hav­ing replaced some of the details of the new device they could get better results which were of great importance for the research concerned. 13. The results obtained were in good agreement with the values involved. 14. A small amount of common salt when added to water will be taken up by the water and become invisible. 15. Having examined the new work carried out by our research workers we could say that various lines of technological progress, ranging from the invention of new devices to the development of some industrial chemical processes were characterized by a steady improvement. 16. The terms insisted on in this statement are to be discussed again. 17. The data derived are to be found in table 5, they being reliable. It’s obvious from the results given above. 18. Surrounding the nucleus were electrons, their number depending upon the atom. 19. The experiment spoken of is to be carried out again. 20. Substances thought of as radioactive should be treated carefully. 21. The con­ference attended by our students was devoted to the pol­lution problem. 22. When solving a non-linear problem described by differential equation, we must first design the computing diagram of the machine. 23. The temperature having been raised, the vapour began forming again. 24. Any neutrons and protons left over after the formation of maximum number of alpha-particles are looked upon simply as being present in the nucleus.

THE SUBJUNCTIVE MOOD AND CONDITIONAL SENTENCES

1. Had they taken into account the weight before heat­ing they would have made less mistakes. 2. Thus, the deu­terium, the nucleus of H² could be considered to be built up from a proton and a neutron. 3. Had the condenser been placed in a direct current the current would have started flowing as though the condenser were not present. 4. Were water allowed to run back into the generator an explosion might result. 5. It is necessary that they should determine whether or not this inorganic substance is contained in the sample to be analysed. 6. It is necessary that atomic energy should be used only for peaceful purposes. 7. A reliable de­vice for neutron storage could greatly simplify the procedure, so that only one detector would be needed. 8. It is desirable that the determination of the effect of glass composition should be made. 9. If no catalyst were employed in cracking, the process would be called “thermal cracking”. 10. If the gas were colourless, we should not notice its formation; we should have noticed the formation of this gas if it hadn’t been colourless. 11. If analytical balances were used the results would be much more precise. 12. If air were a single compound the bubbles escaping from the solution would have the same composition as those of undissolved air. 13. If the liquid were placed between the plates of a condenser and an electric field applied, the molecules would tend to orient themselves both to positive and negative plates. 14. Had water been purified carefully they wouldn’t repeat the ex­periment. Remember: water has to be purified lest it should contain microbes. 15. If two liquids had been mutually in­soluble, neither one would have lowered the vapour pres­sure of the other. 16. It is desirable that the sample should be weighed again as the weight does not confirm our data. 17. If a crucible filled with pure arsenic were heated to a temperature above the melting point of the arsenic, and the system were then allowed to cool, it would be noted that the temperature would increase steadily with time. 18. If pure lead were used the falling drops would solidify rather sud­denly on reaching the temperature 327°C. 19. If we contem­plated water in a glass, the water would appear optically uniform. At any rate, we cannot discern any difference in the appearance of the water at the bottom of the glass and on the surface. 20. If there was no order in the way in which atoms of different elements combine to form the molecules and crystals of compounds, it would be necessary for us to memorize one by one the formulas of thousands of substan­ces. 21. If an electron were to be removed from the sodium atom, leaving only 10 electrons around the nucleus, the resulting particle would have a positive charge, this par­ticle composed of a sodium nucleus and 10 electrons, being called a sodium ion. 22. If the absolute temperature were doubled, the speed of the molecules would increase. 23. If some iodine crystals are put into a flask, which is then stop­pered and allowed to stand at room temperature it would soon be seen that the gas in the flask becomes violet in colour, showing that a quantity of iodine evaporated.

The infinitive

1. Reaction appears to be almost instantaneous at room temperature. 2. To test the validity of these assumption, we have to study the reactions of two representative ni­

trones. 3. However, since the problems to be investigated can­not be solved even in an idealized form by linear differen­tial equation, the differential equation, which we are to use will have to be non-linear. 4. The system under inves­tigation is considered to be in a state of equilibrium, when all the co-ordinates are constant with respect to the time.

5. Hence, the Young’s model appears to be too simple and needs to be modified to fit the present experimental findings.

6. He was always the first to take up the most difficult prob­lems and to solve them. 7. One can hardly expect a true scientist to work in the limits of one narrow field. 8. To find the length of an object was a very difficult task, and we had to carry out a lot of experiments. 9. Once the distri­bution of gas velocities has been calculated, the final step is to determine the nature and extent of the separation of uranium isotopes in the gas. 10. The only practical way was to detect a slow neutron is to allow it to be absorbed by a nucleus. 11. Since we are to deal very largely with ions in our reactions it is necessary to remember that the solution should be diluted. 12. The science of organic chemistry is a very extensive one, and the selection of a small number of facts to be presented in these two chapters has to be re­stricted. 13. Urea was long considered to be the first organ­ic compound, it is known first to be produced in the labor­atory. 14. Nylon is found to have been made in several dif­ferent firms; the first to be produced commercially was the most important. 15. The order of some reactions is known to have been determined by measuring the time required for a constant fraction of reaction to occur. 16. Every living organism can be shown to be made of cells. 17. Since the enzyme concentration in living cells is likely to be difficult to estimate we often speak about their activities. 18. Over the past few years much attention is known to have been given to unimolecular reactions driven by lasers. It has also been stated lasers to find wide application in chemical in­dustry. 19. This assignment is too difficult to be carried out at once, it is to take at least ten days or even more. 20, In qualitative analysis we have to deal chiefly with the ampho­teric characteristics of the hydroxides. 21. Since we are to deal very largely with ions in our reactions it is necessary to remember that the solution has to be diluted to such a degree that the substance is largely ionized. 22. The absorp­tion of a quantum of visible or ultraviolet radiation could be expected to alter the state of excitation of the electronic structure of an atom or a molecule.

Suppleme nta r y rea ding the discovery of the nuclei atoms

In 1911 E. Rutherford carried out the experiment that showed that most of the mass of atoms is concentrated in particles that are very small fn size compared with the atoms themselves. His experiment consisted in bombarding a film of some substance, a piece of metal foil, with a stream of fast-moving alpha-particles, and observing the direction in which the alpha-particles rebound from the atoms.

If the atoms bombarded with alpha-particles were solid throughout their volume, we should expect all of the alpha- particles in the beam to be deflected to some extent. Actu­ally, however, E. Rutherford observed that most of the alpha-particles passed through the metal foil without ap­preciable deflection.

Later Rutherford found that the heavy nucleus has cross-sectional area only 0.00000001 as great as the сих. - sectional area of the atom, and hence that the diameter of the nucleus is only 1/10,000 as great as the diameter of the atom. The picture of the atom that has been developed from experiments is an extraordinary one. If we could magnify a piece of gold leaf by the linear factor 1,000,000,000—a bil­lion fold—we should see it as an immense pile of atoms about two feet in diameter, each atom being about as big as a bushel basket. Practically the entire mass of each atom would, however, be concentrated in a single particle, the nucleus, about 0.001 inch in diameter, like an extremely small grain of sand. This nucleus would be surrounded by electrons, equally small, and moving rapidly about.

TH£ FUNDAMENTAL PARTICLES

All pf the simple particles which exist in nature have been found to undergo,reactions in which they ^are.converted into or obtained from other particles of radiation. There are, then, no particles which can be said to be truly fundamental.

The electron was the first of the simple particles to be recognized, it being, discovered by J, J. Thqmson in 1897, The proton, the nucleus of the ordinary hydrogen atom, was observed as .positively charged rays in a discharge tube. The nature of the rays was not at first understood. The next very simple particle to be discovered was the positron, found in 1932. The positrons were found among the particles produced by the interaction of cosmic rays with matter. They seem to be identical with electrons except that their charge is +e instead of —e. Their span of life as free particles is very short, it being less than a microsecond (lxlO^-6 sec).

The neutron is known to have been discovered by the English physicist J. Chadwick, also in the year 1932. Neu­trons have been found to be particles with mass only slightly larger than that of the proton, and with zero electric charge. They having no electric charge, neutrons interact with other forms of matter only very weakly, and it is accordingly hard to prove their existence by direct method. On passage through solid substances they undergo deflection only when they approach extremely closely to nuclei, that is, when they undergo direct collisions with nuclei. Neutrons and nuclei being so small, the chance of collision is very small and neutrons are accordingly able to penetrate through great thicknesses of heavy elements.

ENERGY

The structure of matter cannot be explained completely in terms of material particles alone. It is necessary to make use of another concept which takes into account the relations of the particles to one another and the extent to which they are in motion. This concept is known to be Energy. A system is said to possess energy if it is able to do work. Work is done when the point of application of a force moves. If a force of 1 dyne moves 1 cm along its line of action 1 unit of work is done. This unit is known as the erg. Work is done in many processes, and may be calculated as the product of two factors if this product is expressible in ergs. For example, when a gas expands against a pressure, we state work to be done; the simplest conditions arise when the pressure is kept constant and the volume is changed, and the work then done is p (V₂—У_г) where p is the pressure (force per unit area), Vi the initial and V₂ the final volume.

Energy which can be released from a system in the per­formance of work must previously have been stored in some

manner within the system. The energy of a system may depend either on the relative positions of parts of it: for instance, a raised weight has energy which can be released as work when it falls; or on the motions of parts of the sys­tem: for example, a moving body possesses energy which can be converted to work in the act of bringing the body to rest. Energy due to position is potential energy; energy due to motion is kinetic energy.

Nuclear chemistry

Atoms are known to undergo certain changes, however, which cannot be explained by changes in the configuration of atomic electrons/’

H. Becquerel was the first to notice that a crystal of a salt of uranium placed on a photographic plate in the dark affected the plate so that an image of the crystal appeared. f He concluded this effect to have been caused by the emission of some kind of ray from uranium.

Shortly after his discovery, the Curies found the intensity of the rays emitted by the pitchblende ore from which ura­nium is obtained to be greater than would be expected from a knowledge of the uranium content.

The enhanced activity was proved to be due to a prev­iously unknown element radium, which occupies the position below barium in Group II of the periodic table.

It was shown that the rays emitted by radium consist of two kinds of particles, called A-particles and B-particles, and an electromagnetic radiation called Y-rays, having a wave length of the same order as that of X-rays. A-particles have been shown to be the nuclei of helium atoms. They are emitted from radium with a speed of about 15,000 miles per second and are able to penetrate a few cm of air, or very thin aluminium foil.

B-rays are electrons; their speed is about 100,000 miles per second.

Organometallic compounds

For the present purposes organometallic compounds may be defined as those having carbon metal bonds, the word bond being taken to include all types of chemical combina­tion or linkage that do not involve in intermediate atom.

This definition excludes, for example, salts or organic acids, amides, esters or ethers of the amphoteric elements,

for in all these carbon is bonded to the metal through a third element.

The formation of organic derivatives is a very general phenomenon.

There are a few elements for which no organic compounds have been isolated, but there appears to be no theoretical reason why such elements should not form organic deriva­tives.

Classifying the very large number of known organometal­lic compounds into a few distinct types is not a simple mat­ter. The properties of an organometallic compound depend both on the nature of the central atom or “parent element” and on the nature of the organic group or groups attached to that atom.

Although a knowledge of the behaviour of the carbon- metal bond is essential to understanding the chemistry of organometallic compounds other factors also are of impor­tance.

A few broad generalizations can be made concerning the trends in chemical behaviour of organometallic compounds. The compounds of the heavier elements are observed to be less stable toward thermal decomposition than those of the light elements.

Photochemistry

Many chemical reactions are caused to proceed by the effect of light. For example, a dyed cloth may fade when exposed to sunlight, because of the destruction of molecules of the dye under the influence of the sunlight. Reactions of this sort are said to be called photochemical reactions. A very important photochemical reaction is known to be the conversion of carbon dioxide and water into carbohy­drate and oxygen in the leaves of the plant, where the green substance chlorophyll serves as a catalyst. One law of pho­tochemistry, discovered in 1818, is that only light which is absorbed is photochemically effective. Hence a colored substance must be present in a system that shows photochem­ical reactivity with visible light.

The second law of photochemistry, formulated in 1912 by A. Einstein, is that one molecule of reacting substance may be activated and caused to react by the absorption of one light quantum, a light quantum being the smallest amount of energy that can be removed from a beam of light by any material system. Its magnitude depends on the fre­quency of the light. In some simple systems the absorption of one quantum of light proved to result in the reaction of; decomposition of one molecule.

PROBLEMS OF CHEMISTRY

The chemistry involves a systematic study of the sub­stances of the universe, of their properties and their reactions with each other to form new substances with different pro­perties and of the conditions governing those reactions.

Were this all, then the chemistry would be little more than a massive catalogue of facts and a collection of tech­niques to be discovered.

But chemistry is also said to be concerned with the clas­sification of data it has acquired and with a series of precise generalizations called laws.

Chemistry is not concerned only with the discovery of laws. Its aim is to find the simplest explanation of these laws—to invent a theory which makes clear the relationship between one law and another.

A number of theories are encountered in chemistry—the atomic theory, the kinetic theory, the ionic theory and the electronic theory of valency.

It is an important feature of scientific theories that they should provide an explanation of facts already known, but they should also lead to a further advance in our knowledge.

FUSION

The basic process of nuclear fusion is well known. If two light atomic nuclei were brought together with enough force to overcome the repelling Coulomb force, they would fuse, yielding a heavier nucleus and at least one other par­ticle (a proton or a neutron, depending on the reaction), the reaction products being all characterized by extremely high energy.

For example one of the possible fusion reactions involves two isotopes of hydrogen (deuterium and tritium) which when they fuse yield an alpha-particle and a neutron with an energy gain of 17.58 million electron volts (mev).

A fusion reactor could consist simply of a container hold­ing a mixture of fully ionized deuterium and tritium nuclei at a very high temperature.

In such a hot plasma fusion reactions would occur when the ignition temperature is reached, at this temperature the energy released by the fusion reactions being equal the energy lost by radiation from the plasma.

The chemistry of polymers I

The chemistry of macromolecular compounds is stated to be one of the most actively developing branches of chem­ical science at the present time, its rapid development could be explained by the fact that the chemistry of high polymer synthesis is involved in progress in such important fields of polymer technology as plastics, synthetic rubbers, synthetic fibres and synthetic film formers.

The synthetic chemistry of polymers proved to have ap­peared in 1883, when Berzelius formulated the concept of polymer ism.

Gay-Lussac is known to have synthesized the first poly­mer. During the subsequent years the field of macromole­cular compounds has been enriched by a large number of new synthetic methods, the contribution of Soviet scientists to polymer chemistry being very substantial.

The works of Butlerov, Lebedev, Shorygin, Kargin, Med­vedev and others are known to have laid the foundations of polymer science.

A great number of chemists is now engaged in synthesis of new polymers, 50% of all organic chemists working di­rectly or indirectly on polymers and a still greater number of scientists being occupied with use of the results of these investigations in industrial production, processing and application of polymers.

To illustrate the extent of work on polymer synthesis it can be stated that now in the course of one year about 50,000 new polymers can be synthesized, i.e. more than 160 new polymers per day or one new polymer every three min­utes. Polymer technology of the future has been stated to be based to a considerable extent on chemical moulding processes. Polymers are known to be used everywhere. Very great advancements have been made in work on polymers disigned for various electrical purposes, such as for produc­tion of insulators, electrically conducting materials, semicon­ductors, etc.

It should be pointed out that some investigators have paid particular attention to the problem of synthesis of polymeric semiconductors and superconductors. The problem to be solved dealt with the production of polymers that are degradable after use, this being particularly important for protection of the environment. This problem could be solved in a number of ways, among which one of the most impor­tant being synthesis of polymers that degrade under the action of light.

Another pressing problem is that of producing polymers for medical purposes having various combinations of prop­erties, such as ability to be absorbed in the organism and conversely resistance to the media of the living organism pharmacological activity, etc. which are known to be nec­essary for construction of an artificial heart, liver and other organs.

A problem of great interest seemed to be that of finding ways of preparing a wide assortment of polymers.

Speaking about polymers it is necessary to say that the methods of synthesis of polymers, namely addition poly­merization, polycondensation and modification of polymers should be considered.

On the basis of information gained it may be stated that research in the field of addition polymerization was mainly concerned with improvement of methods of polyme­rization. It should be also noted that addition polymeriza­tion is being studied very intensively and great advances in this field have been achieved.

In conclusion it should be pointed out that much prog­ress is being made in the field of polymers.

As a result of this, science is being enriched by a large number of new polymers. Finally, an especially characteris­tic feature of contemporary polymer synthesis is the ten­dency to produce polymers designed not only for construc­tional purposes but also heat-resistant, semiconducting and electrically conducting polymers, polymers with photoelec­tric activity, light sensitivity and biological activity, etc.

A large contribution to this field of science has been made by the work of our Soviet chemists.

II

The present state of the chemistry of polymer synthesis and the prospects for its future development are being dis­cussed. The range of monomers used in polymerization and polycondensation and the types of polymers formed are shown in our work.

Attention is drawn to the important fact that all synthe­sis reactions involve formation of polymers containing dif­ferent units. Specific features of the development of polymer synthesis by addition polymerization and polycondensation methods, as well as means of modification of polymers, are of great interest. The diversity of polymerization and polycondensation processes is known to be discussed, as well as the modification of already prepared polymers main­ly by the example of new reactions, especially those leading to production of polymers of a new type.

The chemistry of macromolecular compounds is found to be the most actively developing branches of chemical science at the present time, its rapid development being explained by the fact that the chemistry of high polymer synthesis is involved in progress in such important fields of polymer technology as plastics, synthetic rubbers, syn­thetic fibres and synthetic film formers. In turn production of these materials proved to play an important part in ad­vances in a number of important branches of industry, such as the aviation and automobile industries, the electrical and radio industries, etc.

The carbon dioxide

In the century and a quarter since 1850 human activities have increased the amount of carbon dioxide in the atmosphere of the earth from 290 parts per million or less to slightly more than 330 parts per million. Perhaps a fourth of the total increase has come within the past decade. By the year 2020, if present trends continue, the amount of carbon dioxide in the atmosphere could approach twice the current value. Until recently the increase was commonly attributed to the burning of fossil fuels. Now there is evidence that it may be due in equal degree to another source: the world­wide destruction of forests.

Although carbon dioxide is only a trace gas in the atmo­sphere of the earth, present at a concentration of about 0.03 per cent by volume, it plays a possibly critical role in con­trolling the climate of the earth because it absorbs radiant energy at infrared wavelengths. Heat trapped in this way has a large potential for altering the world climate substan­tially. And quite apart from possible effects on the climate, the carbon dioxide in the atmosphere also plays a critical role as the source of the carbon that is fixed in photosynthe­sis by green plants and therefore provides the basis for all plant and animal life.

Mankind therefore faces a historic dilemma. The human activities that are increasing the carbon dioxide content of the atmosphere promise to bring a general warming of the climate over the next several decades. Although one can not be certain of how much the climate will change, or of the precise mechanisms that will be involved, the results of a steadily rising amount of carbon dioxide in the atmosphere will almost certainly be destabilizing. An increase in the average world temperatures will probably enlarge the area of the arid zones and significantly affect agricultural produc­tion.

Some facts about electrons and protons

At one time, students of electricity used to be told: “We don’t know what electricity is. We don’t know what current is. We don’t knowhow electricity goes through a solid wire.” The electron theory could explain these things clearly and simply. In addition it could explain the true meaning of voltage, resistance, insulation, magnetism, induced voltage and a lot of other phenomena.

Scientists now found our universe to be fundamentally dependent on two factors: one being matter, the other being energy. Matter has been stated to be anything that occupies space and has weight. The composition of matter turned out to be divided into three ingredients, viz: protons, neu­trons, and electrons. The word “proton” gives us a clue that the proton is a positive charge, it having very little weight. The proton proves to carry a positive electric charge, equal in magnitude but opposite in sign to that of the electron. The proton, however, is about 1.820 times as heavy as the electron. The proton could decay into other particles without violating the conservation of either energy or electric charge. For example, electron has an antiparticle called the posi­tron, with the same mass as the electron but with a posi­tive electric charge equal to that of the proton. Inciden­tally, the positron is stable for the same reason. There is nothing in the laws of energy or charge conservation that would forbid a proton from decaying into a positron and ariy number of protons and neutrons.

If we could examine the structure of a piece of copper, for example, we would find that it consists of a specific number of protons, neutrons, and electrons arranged in some particular manner. In a piece of iron a certain number of protons, neutrons, and electrons are arranged in a different way. The proton of iron is found to be identical to that of copper, and similarly for the other elements.

They are all made up of the same ingredients.

The decay of the proton

First of all we shall consider the electron. As far as is known, there are only a few kinds of particles with a mass less than that of an electron, the most familiar of them being the proton, the quantum of light, whose mass is thought to be exactly zero. There are strong theoretical grounds for thinking there is also a quantum of gravitational radiation, the gravitation, again with zero mass. Finally there are various species of particles called neutrons, which prove to be sim­ilar in some respects to the electron, they being emitted in the familiar kind of radioactivity known as beta decay, the kind that was discovered by Becquerel in 1896.

Neutrons have generally been thought to have zero mass, but the determination of their mass is at present an object of intense theoretical and experimental effort.

The quantum theory and reality

Any successful theory in the physical sciences is expected to make accurate predictions. Given some well-defined ex­periment the theory should correctly specify the outcome or should at least assign the correct probabilities to all the possible outcomes. From this point of view quantum mechan­ics must be judged highly successful. As the fundamental modern theory of atoms, of molecules, of elementary parti­cles, of electromagnetic radiation and of the solid state it supplies methods for calculating the results of experiments in all these fields.

Apart from experimental confirmation, however, some­thing more is generally demanded of a theory. It is expected not only to determine the results of an experiment but also to provide some understanding of the physical events that are presumed to underlie the observed results.

When one seeks information of this kind in the quantum theory, certain conceptual difficulties arise. For example, in quantum mechanics an elementary particle such as an electron is represented by the mathematical expression called a wave function, which often describes the electron as if it were smeared out over a large region of space.

This representation is not in conflict with experiment; on the contrary, the wave function yields an accurate esti­mate of the probability that the electron will be found in any given place. When the electron is actually detected, however, it always has a definite position. Hence it is not entirely clear what physical interpretation should be given to the wave function or what picture of the electron one should keep in mind. Because of ambiguities such as this many physicists find it most sensible to regard quantum mechan­ics as merely a set of rules that prescribe the outcome of experiments.

Negative absol ute temperatures

Temperature is a property of matter that seems to have a well-defined range of possible values. If all the heat could be extracted from a body, it would be assigned a tempera­ture of absolute zero, or zero degrees Kelvin, and it could not become any colder. At the other extreme, heat can al­ways be added to a body, at least in principle, and so its temperature can increase without limit. All absolute tem­peratures therefore seem to fall in the range between zero and positive infinity. (Negative temperature on the Cel­sius and Fahrenheit scales arise only because the zero points of those scales do not correspond to absolute zero.)

Temperatures of the kind that are measured with an or­dinary thermometer are indeed confined to the range of pos­itive numbers. There are a few physical systems, however, whose temperature when measured on an absolute scale can assume negative values. What may seem even more peculiar, such temperatures are not colder than absolute zero. The negative temperatures are not “below zero”, they are “above infinity”.

In order to understand how an absolute temperature can be negative, it is first necessary to recognize that a single body can simultaneously include systems of particles that exhibit more than one temperature. In a crystalline solid, for example, the ordinary temperature—the property meas­ured by a mercury thermometer—reflects the average vi­bratory motion of the atomic nuclei; that temperature can­not be negative. The same nuclei, however, have freedom of orientation as well as freedom of motion, and the set of all the orientations makes up an independent system of par- tides that can also have a temperature. It is temperatures of this kind that can take on negative values. Because the energy in question is small, a crystal in which the nuclear orientations are at a negative temperature feels neither hot nor cold to the touch. Negative absolute temperatures are nevertheless real; they can readily be measured and can even be manipulated by the methods of calorimetry.

MEASUREMENT AND CONTROL IN CHEMICAL PLANTS

To produce good-quality products, the chemical indus­try is known to use instruments for accurately measuring and controlling operating conditions.

Good measuring instruments give rapid results, tend to avoid errors, permit automatic control. In the absence of modern instrumentation chemical processes were often con­trolled by a human operator. With modern instrumentation, the quality of the product could be improved and kept' more uniform, than when human operators have to decide, with little or no instrumental help, what to do next.

There are many different kinds of measuring instruments, for example: chemists are known often to use different vis­cometers to control the viscosity.

What is viscosity?

The term “viscosity” applies to both liquids and gases, it being a measure of the thickness or ease of stirring of a fluid.

For example, the viscosity of honey is greater than that of water and fuel oil than that of gasoline. In the labora­tory, viscosity could be determined by an Ostwald viscosi­meter, in which a given volume of liquid is allowed to flow at constant temperature between two marks. The longer it takes for the liquid to pass through, the greater is the vis­cosity. The results are usually compared with those for pure water at the same temperature.

In a chemical plant the viscosity is usually determined by an instrument which gives rapid results and permits controlling the viscosity.

A protein molecule as computer sensor

The research done at the Institute has demonstrated that globular protein molecules can be considered by a number of their indices as solid bodies whose mechanical characteris­tics are equal to those of acrylic plastics of ebonite, the only difference being that a protein molecule is a structure with elasticity varying in different directions. Bearing this in mind one can design what can be termed chemomechanical transducers.

Assume that certain chemical substances to be discovered and analyzed have started to arrive at the computer “input” sensing the development of some technological process. The transducer is to detect their concentration and give a defi­nite signal. Attached to the base, immobilized protein mole­cules pick up the molecules or atoms of other substances and as a result, they change their dimensions by either ex­panding or compressing, which makes it easy to register them. Then the transducer returns to its initial position.

Electron theory

The electron theory can explain electricity, current, in addition it explains the true meaning of voltage, resistance, insulation, magnetism. Therefore, an understanding of the fundamentals of the electron theory is basic to the under­standing of electrical and electronic theory. Scientists now agree that our universe is greatly dependent on two factors, one of which being matter, the other being energy. Matter is anything that occupies space and weight, it existing in any of three forms: solid, liquid, or gaseous.

The composition of matter is known to be divided into three ingredients: protons, neutrons, and electrons.

The word “proton” appears to be a positive charge, it having very little weight.

The neutron has no charge. It supplies practically all the weight of matter.

The electron charge is opposite to the proton; that is, it has a negative charge, it having very little weight.

These are our basic ingredients. If we could examine the structure of a piece of copper, we would find that it con­sists of specific number of protons, neutrons, and electrons arranged in some particular manner.

In a piece of iron, a certain number of protons, neutrons, and electrons are arranged in a different way. The proton of iron is identical to that of copper, and similarly for the other elements, they all being made up of the same ingre­dients.

When we take protons, neutrons, and electrons and make up a small part of iron or copper, we call it an atom. Atoms could be called the smallest recognizable part of any element.

We find the atoms to have first of all a nucleus. The nucleus is composed of the protons and neutrons. All the protons and all the neutrons are grouped into one small mass which is called the nucleus, the charge of the nucleus con­sisting of protons which are positive, and neutrons which have no charge, therefore the nucleus must be positive. A few words should be also added about atomic weights and atomic numbers.

The word “weight” tells us that atomic weight has something to do with the number of neutrons in the atom.

The atomic number corresponds to the number of protons in the atom, and also the number of electrons.

The electrons have been found to be arranged in shells around the nucleus, the maximum number of shells for any known element being seven.

The electrons in the last shell are called valence elec­trons. The electrons are tightly bound to their nucleus. It should be added that in a normal atom the number of elec­trons is equal to the number of protons.

As we have already stated the second fundamental fac­tor of the universe is energy.

Energy has been defined as the ability to do work.

We cannot see energy, but we can notice its effects. Care­ful analysis has proved that energy is actually being lib­erated or converted from one form to another.

New chemistry of an old molecule

Platinum compounds have had a long and distinguished history in the development of inorganic chemistry. Because of the slow rate of dissociation of atoms attached to plati­num in its most common oxidation states, platinum com­plexes have been extensively studied as prototypes for sub­stitution reactions. Platinum has also been widely employed in the chemical industry as a catalyst for naphta reform­ing and is currently a chief component of catalytic convert­ers used to remove toxic substances from automobile ex­hausts. For the past decade, platinum has served medicine in the form of cis-diamminedichloroplatinum, cis-DDP, which has had notable success as an anticancer drug.

The molecule cis-DDP, first synthesized in 1845, was known for many decades as Peyron’s chloride, its structure having been deduced in 1893. The scientists got interested in its mechanism of action as an antitumor drug. Careful scrutiny of the chemical changes taking place when cis-DDP

dissolves in water revealed new compounds that were pre­viously undetected.

Later it was observed that the reaction of cis-DDP with nucleic adds gave blue colors. Blue compounds could also be obtained with the nucleic acid building blocks, the py­rimidine bases and thymine. Although “platinum blues” had been known for nearly a century, their geometric and electronic structure were not understood. Since blue-colored platinum compounds are very rare, it was a challenge to understand these molecules.

CHEMICAL REACTIONS WITHOUT SOLVATION

Chemical reactions are strongly influenced by the sol­vent medium in which they proceed. New technique makes it possible to examine the behavior of so called “bare” chem­ical reactants in the absence of solvent.

Chemistry is the science of molecules. It is concerned with how and why atoms bond together to form molecules and how rapidly molecules can be transformed into new configurations. Most chemical reactions are found to take place in a solvent medium such as water whether they do so in the test tube or in the living cell.

Chemists have long been curious about what happens when solvents are changed or, better yet, when they are removed entirely. In the absence of a solvent would chemical reac­tions still proceed? Would the same products be formed? These questions are very important for a variety of reasons:

First, the fundamental factors that influence reaction rates cannot be studied in solution because the solvent mol­ecules themselves interact strongly with the reacting spe­cies. If the solvent could be totally removed, the intrinsic reactivity of the “bare” reactants could be measured and distinguished from the effects attributable to solvation.

A second reason for having an interest in the role of sol­vation is evidence that in living organisms the active sites on enzyme molecules exclude water, so that they can engi­neer reactions that either would not proceed in bulk water solution or would proceed only very slowly. Some experi­ments can prove these reasons. In these experiments ions, the electrically charged fragments of molecules, undergo chemical reactions totally without interference from sol­vents. The apparatus for conducting the experiments is called a pulsed-ion cyclotron-resonance mass spectrometer.

Studying the reactions of isolated ions and molecules in the absence of solvation is a difficult experimental prob­lem.

WEATHERING

Variations in temperature from day to night and from winter to summer cause expansion and contraction of rock material. Occasionally these changes are known to cause mechanical failure of rock. But it still seems unlikely that temperature changes are great enough to cause extensive mechanical weathering. Theoretically, such changes in tem­perature should cause disintegration. For example, we know different materials which form a granite to expand and con­tract at different rates as they react to rising and falling temperatures. We would expect, then, that even minor ex­pansion and contraction of adjacent minerals would, over long periods of time, weaken the bonds between mineral grains, and that it would be thus possible for disintegration to occur along these boundaries. It’s also been noted that frost is much more effective than heat in producing me­chanical weathering.

When water freezes, its volume increases about 9 per cent. So when water expands as it passes from the liquid to the solid state it sets up pressures that are directed outward from the inside of the rock.

THERMOSTATS

Heat causes substances to expand. This is because heat causes the atoms and molecules in the substance to move more quickly. As a consequence, they take up more space. This is true for gases, liquids and solids, but gases expand much more than liquids, and liquids much more than sol­ids. When a substance is cooled, the molecules slow down and as a result the substance contracts.

Thermostats make use of the principle of expansion. The function of a thermostat is to maintain a constant tempera­ture over a period of time. They are used in refrigerators, heating and cooling systems and many industrial processes.

When different materials are heated, some expand more than other. For example, if brass is heated by one degree Celsius, it will expand by one fifty-thousandth of its length. Heating copper, on the other hand, will cause it to expand by about 90% of this. One kind of thermostat contains a strip of brass and a strip of copper which are joined to form a bimetallic strip. When the strip is heated, the different metals expand by different amounts. As a result, the strip is forced to bend towards the side which expands less. This bending can be used to operate a valve or open and close an electrical circuit.

Such a bimetallic strip is used in central heating systems. It switches off the heaters when the air reaches a certain temperature, and switches them on when the temperature falls. One end of the strip can move while the other is fixed. The free end completes an electrical circuit which controls the gas or oil burner. The strip bends as it is heated. At a certain temperature the strip bends sufficiently to break the contact, thereby switching off the burner. When the air cools, the strip contracts until it makes contact and switches the burner on again.

SOME FACTS ABOUT OXYGEN

Scientists have been looking for ways to protect the liv­ing from the lethal influence of ionizing radiation since the discovery of radioactivity.

More than 30,000 different chemical combinations were tested, but unfortunately none of them were found to be applicable to man due to their high toxicity. It is quite possible to increase the organism’s resistance to radiation in a low-oxygen chamber. But these chambers are known to be very expensive and complicated.

A fairly simple method of protection from ionizing ra­diation has been developed in the USSR. It requires neither a rarefied air chamber nor a special suit.

Air similar to that found at the mountain altitudes of 3.5-5.5 thousand metres above the sea level is pumped in through a face mask. Its oxygen content is twice as low as that of normal air on the plain. Similar mixtures have been used in various investigations of both ill and healthy peo­ple for nearly fifty years. This proportion proved to be the best. The experiments demonstrated that animals survive otherwise lethal doses of radiation after being exposed to such a gas mixture.

Human and animal bodies consist of about 80 per cent water.

Radiation causes it to form compounds which actively enter into reaction with biomolecules of the cells, causing their damage. The lower the oxygen content in the tissues, the fewer such combinations, which means less damage from ionizing radiation. In other words, lower oxygen con­tent results in a greater resistance of healthy normal cells to radiation.

SOMETHING ABOUT WATER

Ancient Romans used to say: “water is everywhere”.

However, the ideas on the true proportions of the dis­tribution of water on the Earth and its true role in the life of our planet was found to have been confirmed only by the latest achievements in hydrogeology. The task of hydro­geology as such is to study the problems of formation of groundwater aquifers. It is very important to study the re­sources and reservoirs of groundwaters.

Water has been found to be involved virtually in all geo­logical processes. Without water the mantle material would not be in the molten state. It proves to change the physical properties of the magma rising in volcanos, sharply reduces the melting point of silicate rocks and largely determines the crystallization process.

Water appears to be totally dissociated, its molecules being split into atoms at a depth of 10 kilometers.

Thanks to new methods of research enriched with theo­retical achievements of modern science, primarily in physics and chemistry, virtually all hydrogeological processes have been found to involve water.

The scientists have pointed out that the utilization of water resources should be cardinally reviewed. The discharge of wastewater into lakes and subsurface reservoirs should be reduced and prevented. Now everybody understands the importance of water.

MYSTERY OF THE CENTURY

For more than 75 years scientists have been trying to explain the Tunguska phenomenon.

On June 30, 1908 people in one of the regions of Central Siberia witnessed a unique event. A dazzling celestial body crossed the sky in a western-north-westerly direction, it being between the Lena and the Lower Tunguska River.

Exploding at about five kilometers above the ground, it emitted in the space of several tenths of a second an amount of energy totalling 10²³-10²⁴ ergs. As it disintegrated it covered a distance of some 20 kilometers. Trees were found to have been knocked down over an area of 2,150 square kilometers, fires broke out, and for several days people saw such atmospheric anomalies as “white nights” and noctilu- cent clouds. After years of efforts scientists have come to the conclusion that the celestial body, which has come to be known as the Tunguska object was no meteorite at all but the head of a small comet.

But still and all this is only a hypothesis, though it appears to be the more convincing of all conjectures voiced. And it should be stressed that recent Soviet and foreign publications show once again how cautious one must be in solving such problems.

It should be said that the past two years have witnessed a marked interest in the scientific world in the Tunguska object problem. Though scientists have been investigating the phenomenon for 75 years, there is still no consensus of opinion.

Thus, the basic question concerning the chemical, and isotope composition of the Tunguska object, and to what class of cosmic objects it belongs, is still to be solved.

Associated researches have been conducted for several years under the direction of the Soviet space chemist Koles­nikov. The evidence assembled has confirmed a previously suggested hypothesis, that in composition the Tunguska object approximates that of carboniferous chondrites, they being a variety of stone meteorites. When it disintegrated the ground was covered by much cosmic matter rich in the lighter elements, primarily carbon and hydrogen.

It has been also stated that large quantities of meteor “background” dust fall upon the Earth annually. Soviet scientists have proved that definite portion of the matter discovered by them is from the Tunguska object, but though much has been done, much is to be done.

MAGNET “SEES THROUGH” ALLOYS

Modern technology puts steadily increasing demands to the quality of alloys and steel. This is known to depend on the microstructure of the metal, the order in which its crystals occur, and the orientation of the crystalline grains in polycrystals, i.e., on the “texture” of the material. This quality could be improved if we learnt how to measure the deficiencies in the “packing” of the crystals and control the quality of the metal we produce.

Now there are two tested methods of taking a look into the structure of a material, one being the optical, using powerful microscopes, and the other being X-ray technique. Both involve considerable practical difficulties and cannot be applied in all cases.

Research-workers of the Institute of Metal Physics at the Urals Research Centre of the USSR Academy of Sciences have developed their own method and their own instrument. This new instrument weighs only 5 kilograms, and now it takes less than one minute to measure a metal sample with it; this instrument is known to be used now at metallurgical works in the Soviet Union and other socialist countries.

YOUTH AND PROTECTION OF NATURE

Ecological problems were specially discussed at the 12th World Festival of Youth and Students for the first time in the festival’s history. The Centre for Environmental Pro­tection was set up for this purpose together with the 15 other thematic centres. Some 600 researchers, and people from ecol­ogical youth organizations from over 80 countries took part in the centre’s work.

The centre’s programme covered the cause of the ecolo­gical crisis, the ways of overcoming it, national programmes for environmental protection, the influence of the arms race on nature, problems of the World Ocean and problems of urbanization. Meetings were held with prominent experts, and activists of the All-Russia Society for Nature Protec­tion which has a membership of 35 million people, a half of whom are schoolchildren. An exhibition on environmental protection in the USSR has been arranged with ecological

films. ■

The further development of ecological events can be made more reasonable only through joint efforts to draw all young people on Earth into action.

Moscow, host of the Festival, is a city from which more than 80 industrial enterprises have been removed over the last few years. Today it is one of the world’s cleanest and greenest cities.

CONVERSATIONAL FORMULAE

(Some dialogues to be remembered)

Dialogue 1

A: When do you usually get up?

B: As a rule I get up at 7 a.m.

A: It’s rather early, isn’t it?

В: I shouldn’t say so. You know I live rather far from the Institute.

A: I see. How much time does it take you to get to your Institute?

В: Well, if I go by bus it takes me 35 minutes. If I take the underground it takes me less time.

A: Do you like to go on foot?

B; Oh, yes, if the weather is fine, and I’m not in a hurry, I like to go on foot.

Dialogue 2

Boris: Peter, wake up, it’s time to get up. It’s half past seven. Peter: I’ll be ready in a minute.

Boris: Have you washed? Let’s have breakfast.

Peter: Oh, yes, I’ve already washed, and shaved. Is break­fast ready? I’m hungry as a hunter.

Boris: Everything is ready. Here are some sandwiches with sausage and cheese and tea.

Peter: Thank you, Boris, but I don’t see the sugar-basin. Boris: Here it is.

Peter: Thank you, Boris.

Boris: Don’t mention it.

Dialogue 3

A: Hello, Boris. How are you?

B: Hello, Ann, thank you. I’m fine and how are you?

A: I’m well too. Are you going home?

B: Oh, no, I have got two more lectures, the lecture in gen­eral chemistry, and in the history of CPSU. Have you any lectures today?

A: No, I have two seminars and then English. I am to be free at a quarter to four. Shall we go home together? B: Certainly, I’ll wait for you downstairs.

Dialogue 4

W; Where do you live?

A: I live in a new district. I rent a room, what about you? W: I live in the hostel not far from the University. It is

a new comfortable building.

/i: You are lucky then.

Dialogue 5

W: Do you take part in the students’ scientific society? B: Certainly, I have been carrying on my research work for 2 years already.

W: Who is your supervisor? Does he help you much?

В: My work is supervised by a senior research-worker, he helps me very much. Next month I am to make a report at the conference, therefore I have to work very hard.

Dialogue 6

Teacher: Good morning, comrades. Who is on duty today? Student: I’m.

Teacher: Is everybody present today?

Student: No, Klimov is absent, he is ill.

Teacher: Is everybody ready for the lesson?

Student: Yes, everybody is ready for the lesson.

Dialogue 7

N: Hello, Ann. When will your winter examinations begin? A: Oh, very soon. Here is the time-table of my exams.

N: How many exams are you to take?

A: Oh, I’ll have to take five exams.

Dialogue 8

N: Hello, Ann. Have you already passed your exams?

A: Not yet. I have to take two more exams, I’m afraid to fail in chemistry.

N: Don’t worry, I'm sure you’ll pass it. What mark did you get for the structure of matter?

A: I got five. I’m interested in this subject, besides the lec­tures delivered by professor Sergeev were very interest­ing. All the students attended them willingly.

Dialogue 9

• Hello, Nick. What are you doing here?

• Hello, Ann. I’m late for the lesson.

• Oh, it’s very bad, you have to get up earlier.

Dialogue 10

N: Do you go in for sports?

A: Certainly, I’m keen on volley-ball, besides that I like skating and skiing. And what about you?

N: Unfortunately I have no time to go in for snorts hut on Sundays I play chess or go skiing. ’

Dialogue 11

Is wrong.

P: I think so ... .

Dialogue 12

Marry; Why are you late?

^Л,Ш: 7 Tharp ^{I m JUSt} '^{n time}’ ^l0°^{k at your watch}- It’S'

Marry: No you are wrong it’s a quarter past seven, you are fifteen minutes late. > У «

Ann: Oh, no, your watch is fifteen minutes fast

marry: Oh, I m sorry, Ann.

Remember the following:

A. M.~ in the morning P. M.= in the evening

ЧАСТИ РЕЧИ (THE PARTS OF SPEECH)

Существительное (The Noun)

Образование множественного числа существительных

Множественное число имен существительных в англий­ском языке, как правило, образуется:

1. прибавлением окончания -s к форме единственного числа:

a book — books [-s] a pen — pens I-z]

2. прибавлением окончания -es к существительным, которые в единственном числе оканчиваются на -s, -ss, -X, -sii, -ch, -о:

a match — matches [-iz] a class — classes a box — boxes a hero — heroes l-z]

Падеж (The Case)

В современном английском языке сохранилось только два падежа существительных: общий (the Common Case) и притяжательный (the Possessive Case).

Существительное в форме притяжательного падежа выполняет функцию определения другого существитель­ного и занимает место перед определяемым существитель­ным.

Притяжательный падеж существительных в единствен­ном числе образуется путем прибавления апострофа и буквы s (-’s) к форме существительного единственного числа в общем падеже. Во множественном числе к суще-

* —893

8 —893

11 Англо-русский частотный словарь по химии и химической техно- логии/Под ред. Г. Б. Архипова и л. Эдед.— Изд-во вхту, внр, 1983.

1 Glue — клей