Some Properties of Matter. Грекова О.А. - 3 стр.

                                                         3
                             Unit 1
I Pre-reading task:

1. Check up the meaning of the following words:
Verbs: condense, prevail, boil, melt, exist, vary, emphasize, bind (bound, bound), liquefy,
solidify.
Nouns: solid, liquid, steam, spout, drop, pressure, vessel, clay, inch, treatment, crust.
Adj: invisible, tiny, minute, rare, noble, aerated (drink), troublesome, pure, crystalline.
Adv: naturally, relatively, rapidly, nearly, tightly, somewhat to and for.
2. Guess the meaning of the following words:
Silicon, neon, argon, oxygen, zinc.

II Reading:

1. Read the1st part of the text.

                                              Some properties of matter
                                                   I
       Matter can exist in three forms, solid, liquid, and gas. However, these are not different
classes of matter, but different states – that is, whether a particular substance, say the metal
zinc or water or nitrogen, exists as a solid, a liquid, or a gas depends upon the temperature, and
especially, in the case of gases, the pressure.
       Water is the simplest example. At the low temperature which prevails in many parts of
the world, especially on the mountain-tops, water exists naturally in the solid form. When
water boils it turns into an invisible gas, steam. You must not be misled by the cloud that
forms near the spout of a boiling kettle, for this consists of tiny drops of hot water formed by
the steam condensing in the relatively cold air.
       Consider the metal zinc, which we call a solid, for such it is at ordinary temperatures. It
melts to a liquid at 419o C., and this liquid boils to an invisible gas at 907 oC.
       Now take the gas nitrogen, which is the main part of our atmosphere. At a very low
temperature of – 196o C. and ordinary atmospheric pressure, it turns to a liquid, at a lower
temperature, - 210 o C., it becomes a solid. All gases have now been liquefied and solidified,
although some require a high pressure and low temperature to condense them. Liquid air,
nitrogen, and oxygen are much used in some branches of industry and can be bought like any
other liquid. Of course they require special vessels to prevent them boiling away rapidly at
ordinary room temperature.
       Whether, then, a substance exists as solid, liquid, or gas is a question of pressure and
temperature, not of constitution.

                                      Comprehension check:
a) What are the states of the matter? Give the examples.
b) Which substances are much used in different parts of industry?
c) Complete the statement: constitution, gas, pressure, solid, temperature, liquid.
Whether a substance exists as: .........., ........., or .......... is a question of .......... , and ........., not
of ...... .

2. Read the 2 nd part of the text.