Lesson 3. Part a.

affect	впливати
application	застосування
attempt	спроба
attention	увага
average	середній, середнє число
centigrade	Цельсій
certainly	звичайно
chamber	камера
channel	протока, канал
charge	навантаження, заряд
collide	зіткнутися
combustion	згорання
conduct	проводити
connect	з’єднувати, сполучати
consequently	отже, тому
constant	постійний
convert	перетворювати
dimension	розміри, обсяг
due to	завдяки
evident	очевидний
exist	існувати
expansion	розширення
expend	розширювати
fission	розщеплення
force	сила
freer	замерзати
gaseous	газоподібний
generation	покоління
grade	градус
helium	гелій
hence	віднині
inversely	обернено
linear	лінійний
liquid	рідина
matter	речовина
modern	сучасний
observe	спостерігати
obtain	одержувати
perfect	досконалий
plane	площина
plasma	плазма
possible	можливий
pressure	тиск
property	властивість
quantity	кількість
random	випадковий
relation	відношення
research	дослідження
rotate	обертати
shape	форма, обрис
simultaneously	одночасно
solid	твердий
substance	речовина, матерія
suppose	гадати, вважати
teach	вчити
universe	всесвіт
various	різний
vessel	посуд
volume	обсяг
well-known	відомий
wire	дріт, провід

Exercise 1. Read and translate the text.

Four States of Matter: Solid, Liquid, Gas, Plasma.

A number of Greek philosophers (about 490-430 before our era) taught that the material universe was built of four "roots": earth, water, air and fire. This in modern terminology may be compared with the four states of mat­ter: solid, liquid, gaseous and the plasma state, respecti­vely.

One might ask: "Can every substance exist in all of these four states?" Many substances can do at various-times exist in more than one of the four possible states. That state depends on the substance itself as well as on its volume, temperature and pressure. Ordinary air, for example, condenses completely to a liquid if the tempera­ture is lowered to 196° below zero Centigrade. It would become a solid provided the temperature were further lowered to – 218° C.

Suppose that one could live in a world where the ave­rage temperature were 250° C. At our ordinary pressures, water and ether would be in a gaseous state. On the other hand, was the temperature — 250° C, the substances just mentioned would be solids at that very atmospheric pres­sure. Of no less interest is the fact that the only liquids existing would be hydrogen and helium.

If we think of the substance that we call "water" we generally think of it as a liquid. It does not mean that that is the only possible state in which water does exist. That the liquid stale is the normal state for water is a well-known fact. But water, as anyone must know, can also exist in a gaseous state, i.e., as steam and as a solid, i.e. ice.

The same number and kind of molecules are present in a kilogram of water, steam or ice. However, these molecu­les move differently in each of the above-mentioned sta­tes, hence, their widely varying characteristics.

Let us turn our attention first to solid bodies. The mo­lecules of solids are able to move only through a limited range. The motion of the molecules of a solid is harmonic in type. The molecules move between fixed limits back and forth on either side, of an "average" position and sel­dom pass outside those limits. It is a solid that has both volume and shape.

The reader should certainly know that the molecules of liquids are in a state of constant, random motion. Howe­ver, there are attractive forces exerted on each molecule by the surrounding molecules. Thus, a given molecule is free to move within the liquid itself but is not likely to leave its surface unless it moves very fast. The rather lar­ge forces of attraction exerted on that molecule by the surrounding molecules serve to fix the volume of a given liquid although its shape is changeable.

It is to the gaseous state that we shall turn our atten­tion now. Experiment shows us that there is very little attraction between the molecules of any gas. The gas molecules move, with an almost perfect freedom, very little force being exerted on one molecule by the molecules sur­rounding it. The molecules move rapidly in every di­rection, colliding with one another, expanding to occupy every portion of the container, bombarding the walls of the container. Gases, therefore, have no fixed volume or sha­pe. Their volume and shape depend on the vessel that contains them.

The fourth state of matter, the plasma, consists of neu­tral atoms, ionised atoms and electrons.

Exercise 2. Give Ukrainian equivalents of the following words.

liquid, philosopher, teach, universe, earth air, gaseous, respectively, substance, various, although, hence, inversely, evident, affect.

Exercise 3. Give English equivalents of the following words.

градус, Цельсій, сила, провід, увага, звичайно, відомо, ємність (посудина), матерія, заряд.

Exercise 4. Answer the questions.

1. What are the four states of matter?

2. What did the Greek philosophers teach?

3. Do many substances exist in more than one of the four possible states?

4. What does the state of a substance depend on?

5. At what temperature does ordinary air condense?

6. Does water exist in a gaseous state?

7. Why has a solid both volume and shape?

8. What does the shape of a gas depend upon?

9. What does the plasma consist of?

Exercise 5. Translate the following sentences.

1. If a solid is heated it will expend.

2. On our planet plasma has to be generated by special physical processes and under special conditions.

3. It is the molecules of liquids that are in a state of constant random motion.

4. Air does condense completely to a liquid when the temperature to a liquid when the temperature is lowered to – 196 C.

5. Life on our planet would be impossible unless there were water.

6. Of particular interest is the fact that we are faced with limit less possibilities in future applications of the plasma.

7. It is plasma properties that our physicists study.

Exercise 6. State if the following sentences are true to the fact or false. Correct the false sentences.

1. There are two states of matter, namely liquid and gas.

2. Many substances exist only in one state.

3. The molecules of solids are in a state of constant, random motion.

4. There is very little attraction between the gas molecules.

5. The plasma consists of neutral atoms, ionised atoms and electrons.

Exercise 7. Form nouns from the verbs given bellow.

to achieve, to combine, to contribute, to exist, to compose, to divide, to teach, to express, to increase, to weigh, to develop, to discover, to change, to predict, to know.

Exercise 8. Write out key-words and phrases from the text. Make up a plan of the text.

Exercise 9. Retell the text.