I. Прочитайте и переведите текст. Liquids

The liquid state occupies an intermediate position between the gaseous and solid states, liquid having a definite volume but no definite shape.

Like a gas, a liquid can take the shape of any vessel in which it is put, but in contrast to a gas, a definite quantity of liquid is required for filling the vessel. A liquid can’t be compressed so much as a gas because it’s molecules are already close together, large pressure producing small changes in volume.

Increasing the temperature increases the kinetic energy of all molecules.

The change of a liquid into the gaseous or solid states being dependent upon the kinetic energy of the molecules, which in turn is dependent upon the temperature, there are definite temperature characteristics for most liquids at which these changes occur. The are known as transition temperature.

If we place one liquid layer carefully on top of a layer of a more dense liquid in which it is soluble, and set the vessel where it won’t be disturbed, we shall see that two liquids begin gradually mixing. It is also to be taken into the consideration that all liquids do not flow with the same ease, water, alcohol, gasoline flowing easily, while heavy oil, glycerine flowing very slowly.

When a liquid flows, layers of molecules begin rubbing over each other, friction being generated by this rubbing of layers of particles. The greater the friction, the slower is the flow. A liquid which resist flowing, or resist the action of any other deforming force upon it results in a homogenous solution. We give this example for illustrations that the molecules of a liquid diffuse, though much more slowly than do those of a gas.

The molecules of a liquid are much closer together than they are in a gas, because of the greater relative strength of attraction, the density of liquids being much greater. Naturally as the volume of a liquid begins varying with temperature it’s density will also start varying with temperature.

It should be noted that the closeness of the molecules also is known as viscous, the opposite of viscosity being fluidity. Viscosity diminishes and fluidity increases with temperature.

Vocabulary

1. intermediate – средний, промежуточный

2. vessel – сосуд

3. to compress – сжимать

4. layer – слой

5. to disturb – нарушать

6. mean – средний

7. gradually – постепенно

8. in turn – в свою очередь

9. to rub – тереть

10. friction – трение

11. viscosity – вязкость

12. fluidity – текучесть

13. to enable – позволять

14. surface – поверхность

15. dense – плотный, густой

16. to flow – течь

17. density – плотность

18. to diminish – уменьшаться

19. velocity – скорость

20. to escape – улетучиваться

21. to fill – наполнять

II. Выполните упражнения

1. Ответьте на вопросы

1. What position does liquid state occupy? 2. What shape does liquid take? 3. Is it possible for a liquid to be compressed? 4. Why is it impossible? 5. What does the change of a liquid into the gaseous or solid states depend on? 6. What will happen if we place one liquid layer on top of a layer of a more dense liquid in which it is soluble? 7. Do all liquids flow with the same ease? 8. What is the friction generated by? 9. Why are the molecules of a liquid much closer together than those of a gas? 10. What is evaporation?