1.6. Read the following text and say if it is true that interatomic distance is fixed in all states of a metal. Read again to answer the questions after it.

Vocabulary

state n	—	состояние
matter n	—	вещество
condition n	—	условие
solid a, n	—	твердый, твердое тело
liquid a, n	—	жидкий, жидкое тело
fluid n	—	текучая среда (жидкость или газ)
assume v	—	принимать (форму)
neither … nor conj	—	ни … ни
compressible a	—	сжимающийся
disrupt v	—	разрушать
ultraviolet light	—	ультрафиолетовое излучение
X-rays n	—	рентгеновские лучи
discharge n	—	разряд
orderly a	—	упорядоченный
arrangement n	—	расположение, структура
heat v	—	нагревать(ся)
melt v	—	плавить(ся), таять
convert v	—	превращать
boil v	—	кипеть
vapour n	—	пар
cool v	—	охлаждать(ся)
steam n	—	пар (водяной)
interatomic spacing	—	межатомное расстояние
specific volume	—	удельный объем
boiling point	—	точка кипения
diminish v	—	уменьшать(ся)
contract v	—	сжимать(ся)
freeze v	—	замерзать, застывать, затвердевать
relative a	—	относительный

Three states of matter

Under normal conditions there are three states of matter: the solid state, the liquid state and the gas state. Iron, nickel and other metals are normally solids. Water is normally a liquid and carbon dioxide is normally a gas.

A solid is matter having a definite shape and volume not easily changed by mechanical force. A liquid is matter having no definite volume, but being a fluid, it assumes the shape of its container. A gas possesses mass having neither permanent volume nor shape. Gases are very different from liquids and solids in that gases, having no definite volume, are compressible; solids and liquids are highly incompressible.

The constituent molecules of a gas can be disrupted by subjecting them to ultraviolet light or X-rays, to an electric discharge, or to intense heat. We call an ionized gas a plasma.

All metals in the solid state are crystalline because of the orderly arrangement of their component atoms. When a solid metal is sufficiently heated, it melts and is converted into a liquid; if heating is continued, the liquid eventually boils and the metal is transformed into a vapour.

The atoms in vapour are widely separated and their arrangement changes continuously, but at any given instant it is completely unordered.

As a gas is cooled, it condenses into a liquid metal as steam condenses into water. In this state, the average interatomic spacing is fixed, and so, therefore, is its specific volume at any given temperature. In the liquid state the atoms are not arranged in any definite order.

As the temperature of a liquid drops below the boiling point, the average interatomic distance diminishes continuously and the liquid contracts. As a metal freezes, its component atoms assume a permanently ordered arrangement relative to each other that is the essential characteristic of a crystalline material.

1. How many states of matter exist under normal conditions?

2. In what state does matter assume the shape of its container?

3. What changes in physical state can a solid metal undergo when it is sufficiently heated?

4. Can a gaseous matter have a permanent volume and shape?

5. Are solids easily compressible?

6. What do we call an ionized gas?

7. To what extent are the atoms of a metal separated in vapour?

8. What occurs when the temperature of a liquid drops below its boiling point?

9. What arrangement do the component atoms of a metal assume when it freezes at last?

10. What is the essential characteristic of a crystalline material?

1.7. Look at the table below and identify the tenses.

Active Voice	Passive Voice	Active Voice	Passive Voice
make → is made		had made → had been made
is making → is being made		will make → will be made
was making → was being made		will have made → will have been made
made → was made		can make → can be made
have made → have been made

1.8. Identify the tenses of the passive verbs and translate the sentences.

1. With the time new ways of metal production and treatment were developed. 2. Much is being done to improve our research work conditions. 3. The question about the new laboratory was being discussed at a special meeting at 3 a.m. yesterday. 4. The composition of steel is affected by various ingredients. 5. At university, lectures and seminars are followed by examinations. 6. The project was approved, but the engineer was shown some drawbacks that could easily be corrected. 7. You will be informed as soon as the drawings are received. 8. New knowledge of the stresses and strains in tube tunnels has been obtained by special tests. 9. The weight of the mechanical part had been greatly reduced.

1.9. As may have different meanings: когда, как, так ... как, в качестве, так как. Read and translate the sentences.

1. She works here as a teacher.

2. I can’t run as fast as I used to.

3. I saw Peter as I was getting off the bus.

4. As the time passed, things seemed to get worse.

5. As we are both tired, let’s have a break.

6. As it is late, I must be off.