The Nuclei of Atoms

In 1911 the British physicist Ernest Rutherford carried out some experiments which showed that every atom contains, in addition to one or more electrons, another particle, called the nucleus of the atom.

Every nucleus has a positive electric charge. It is very small. It is about as big as an electron. It is very heavy.

There are many different kinds of nuclei. The nuclei of the atoms of one element are different from the nuclei of the atoms of every other element.

LESSON 4

Grammar: 1. The Adverbs.

2. The use of very, the very.

3. Text: The Nature of Ceramics.

Ex. 1. Pronounce the following words:

ceramics non-metallic

natural matrix

variety primarily

strength covalent comparatively particularly

vacancies

durable neighbour

surprising ionize

pottery resistant

lustrous silicon

ruby aluminium

refractory giant lining

Ex.2 Перекладіть речення.

1. The reaction of carbon with oxygen is highly exothermic. 2. Up to now chemistry has largely been a matter of taking natural products of the earth and converting them to man's uses. 3. This element exists in two readily recognizable modifications: crystalline silicon and amorphous silicon. 4. Mercury oxide can be readily decomposed by heat. 5. There are many reactions which proceed readily, some even violently, if a trace of water is present. 6. For nearly two thousand years it was believed that all heavy objects fell faster than light ones. 7. One of the properties common to nearly all nuclear radiations are particles in their ability to ionize. 8. Hydrogen readily combines with fluorine and chlorine, 9. In many cases mixtures and compounds are not so readily distinguished. 10. There is hardly any living substance in nature which does not consist of compounds containing oxygen.

Ex. 3. Вставте слова"to find" or "to find out" згідно зразка:

Model: 1. At last he found the article about the new methods of production of some synthetic products,

2. He carried a number of experiments as he wanted to find out the composition of this new substance.

1. After many years of hard work the scientist , . , a new method of purifying water. 2. I should like . . . where this scientist will make his report about the refining of petroleum-3. This material . . . wide application everywhere. 4. If you like ... about his new investigations in the field of me tallurgy, you had better speak to him. 5. Have you . . , what the term "chemical durability" means?

Ex. 4 Перекладіть речення.

1. This is the very material we need in our experiment. 2. At the very end the text was very difficult. 3. The very first step in applying the scientific method is to obtain some facts by observation and experiment. 4. He knows the subject very well as he works very hard. 5. In the very nature glass is brittle. 6. This is the very man who can help you.

Ex. 5. Перекладіть речення.

1. These investigations provided new methods of detecting very minute quantities. 2. Provided the temperature is kept constant the volume of a given amount of gas is inversely pro­portional to its pressure and directly proportional to its ab­solute temperature. 3. The steel may be provided with the desired degree of hardness. 4. The laboratory is provided with gas and running water. 5. The expedition was provided with food for many days. 6. Provided the relative pressure of water is higher in the atmosphere (surroundings), vapour will condensate.

Ex. 6 Перекладіть словосполучення

main industrial products; mainly in industry; chemists are interested in this method; a very interesting new method; primarily ionic; is of prime importance; the very substance; a very good substance; by means of; the means of; nearly all the substances; near the limit.

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TEXT. THE NATURE OF CERAMICS

One of .the first solid materials, if not the very first, that man learned to use was a ceramic natural stone. It was used in a variety of applications because of its characteristic properties such as hardness, strength to chemical attack which make it comparatively easy to shape, Thus natural ceramics provided man with tools, durable containers and even a roof. It is not surprising that man got greatly interested in ceramics and tried to create ceramics such as: pottery, bricks, concrete, glass. These products are spoken of as main industrial products to this day.

Ceramic materials have been extended greatly-. They range from dull clay to lustrous ruby, from the refractory linings to electronic, control devices.

What is ceramics? Can this question be answered? Essentially it is defined as a combination of one or more definite metals with- a non-metallic element, usually oxygen. The comparatively large oxygen atoms serve as a matrix with the small metal atoms. The main characteristic of the construction of ceramic crystals is that the atoms are linked by bonds that are primarily ionic but also to a significant extent covalent. These bonds are responsible for the stability and strength of ceramic materials. In the combination of oxygen atoms with metal atoms the ionic bonds are particularly strong. It should be noted that each oxygen atom with two electronic vacancies in its outer shell borrows two electrons from its metal neighbours, thus both kinds of atoms become highly ionized—one negatively, the other positively.

As highly -oxidized compounds the ceramics are strongly resistant to attack by nearly all chemicals. This accounts for many of their uses, even the making of steel depends on the use of ceramics.

A lot of analyses have been made by chemists. They found that the principal elements, for instance, in natural clays were oxygen, silicon and aluminium. They form the compounds known as aluminosilicates.

But a giant step forward in ceramic science., came when crystal structures were analysed by means of X-ray diffraction. It has been found out that in the construction of ceramic materials much depends on how the atoms are stacked.

Ex. 6 Дайте відповіді на питання

1, What was the very first solid material that man began to use? 2. What did natural ceramics provide man with? 3. Why was ceramics used in a variety of applications? 4. Why did man get interested in ceramics so much? 5. What is ceram­ics? 6. What is a main characteristic of the construction of ceramic crystals? 7. Why are the ceramic materials so strongly resistant? 8. What are the principal elements in natural clays? 9. What does the construction of ceramic materials depend on? 10. Why are ceramic materials mass-produced? 11. Why is the ceramic industry so important?

Ex. 7 Відкрийте дужки. Перекладіть речення.

1. Last year our plant {produced, produces) many ceramic goods which (are used, were used) widely. 2. At first man (baked, has baked) vessels of clay in the sun. 3. Recently ce­ramic compounds (are used, have been used) even in making steel. 4. Numerous analyses (have been carried out, had been carried out) before they stated the exact composition of this compound. 5. Now many scientists (are working, work) at the investigation of the new properties of ceramics. 6. Many new discoveries (took place, have taken place) since the last century. 7. Last week they (analysed, analyse) crystal structure of those new materials by' means of X-ray diffraction. 8. For many years considerable_vwork (has been carried out, was car­ried out) to convert ethylene into motor fuel. 9. Many beautiful articles made of ceramics (provided, provides) man with tools even in ancient time.

Ex. 8. Знайдіть пари антонімів і запам’ятайте їх

hard, solid, fast, light, dull, difficult, heavy, bright, weak, easy, liquid, slow, soft, strong.

Ex. 9. Відкрийте дужки, підбираючи необхідне слово

1. (The very, very) first subjects we studied in the first year were mathematics, inorganic chemistry and English. 2. This was (very, the very) book I needed for my work. 3. Have you (found out, found) what subject he was interested in? 4. I shall use this new material (provide, provided) it is resistant to corrosion. 5. She could (hardly, hard) use this material as it was too brittle. 6. These ceramic materials are (light, heavy) in weight. 7. This solid material was (very, the very) good for construction.

.

Ex. 10. Перекладіть текст. Напишіть його короткий зміст

Pottery, porcelain, brick and tile are all very similar in composition and method of manufacture, and with glass they provide the class of materials known as ceramics. These products are made from varying mixtures of clay, silica, and feldspar.

The very first of them are usually prepared from natural clays which already contain silica and feldspar. These natural clays are made into a workable mud with water and then fired in special ovens. As the temperature rises, water is first driven from the mixture, then various decomposition products are formed and above 1250° C the feldspar fuses and binds the other materials present.

Porcelain is made from a very fine white clay known as kaolin. Then very pure sands and feldspars are added. Very soft porcelain is obtained if one adds calcium phosphate to the mud.

Ex. 11, Перекладіть текст

Glass

Silicate materials include glass, porcelain, enamels and cement.

Ordinary glass is a mixture of silicates in the form of supercooled liquid. It is made by melting a mixture of sodium carbonate (or sodium sulphate), limestone and sand.

Ordinary glass contains about 10% sodium, 5% calcium, and 1% aluminum, the remainder is silicon and oxygen. It consists of an aluminosilicate tetrahedral framework, within which are embedded sodium ions and calcium ions.

Cement

Portland cement is an aluminosilicate powder which sets to a solid mass on treatment with water. Portland cement before treatment with water consists of a mixture of calcium silicates and calcium aluminate. When treated with water the calcium aluminate hydrolyzes and forms calcium hydroxide and aluminum hydroxide. These substances react further with the calcium silicates and produce calcium aluminosiiicates in the form of crystals.

LESSON 5

Grammar: 1. Modal Verbs and their Equivalents.

2, Revision of the Passive Voice.

Text: Laboratory

Ex. 1 Поставте речення в минулому неозначеному часі

1. He can speak English quite well. 2. He is to be at home at 7 o'clock. 3. She has to work at home today. 4. They must be very attentive at the lessons.

Ex. 2 Завершіть речення як у зразку.

Model I: I have missed many lessons and now I have to work very hard.

The results of their experiments were bad, they had to repeat them.

1. He has worked very hard this month, he ... a little now. 2. This substance is very rare, if you want to use it, you . . . before the experiment. 3. They used analytical balances as they . . . very minute quantities. 4. The water is very cold, you . . , before drinking it

Model II: I cannot attend the lecture as I am to be at home at six.

1. Don't be late, the meeting ... at five sharp. 2. He ... his research work by the end of this year, that's why he is so busy. 3. The temperature ... to 100°C if you want to finish your experiment in time. 4. Don't you know that she ... at three, it will take her an hour to get here.

Ex. 3. Вставте слова "to have to" or "to be to":

I. I can't go with them as I ... (to be) at the Institute at half past nine. 2. If you want to understand this phenomenon better, you ... (to look through) some articles devoted to this problem. 3. As this question is not solved the meeting . . . (to be put off). 4. At ten a.m. he ... (to make a report), I think it will be interesting to listen to him. 5. As he made many mistakes in his last work he ... (to rewrite) it.

Ex. 4 Порівняйте речення. Перекладіть їх

1 They washed glassware well. Glassware was washed well.

2. The professor referred to this new book.

The new book was referred to by the professor.

3. The student sent his friend to the library. The student was sent to the library.

4. The students have answered all the questions.

The students have been answered all the questions.

5. He spoke much about this new invention. He was much spoken of.

6. He insisted on these conditions.

These conditions were insisted on (by him).

7. Large quantities of sulphur have been produced recently at the plants.

They have produced large quantities of sulphur recently

Ex. 5. Вставте слова "can", "must", "may":

1. I ... help you yesterday as I came very late from the Institute. 2. You . . . understand now that it is necessary to do everything in time. 3. ... I take your dictionary? I have lost mine. 4, Yesterday he. . . come to the library as he had a meeting. 5. They . . . prepare everything for the experiment tonight. 6. If you want, you . . , read this article

Ex. 6 Перекладіть речення.

1. He was told to be in time. 2. She was asked to help him. 3. They were sent to the plant. 4. He was sent for. 5. The professor was sent for. 6. The speaker has been listened to with crreat interest and attention. 7. The new discovery is much spoken of in our Institute. 8. They will be given a very im­portant task

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