3 Part One. The Predicate

The Nature of a Gas
That the molecules of a gas are not held together, but are moving freely in a volume rather large compared with the volumes of the molecules themselves is the characteristic feature of a gas. The Van dcr Waals attractive forces between the molecules still operate whenever two molecules come close together, but usually these forces are negligibly small because the molecules are far apart. Because of this freedom of molecular motion, a specimen of a gas does not have either definite shape or definite size. A gas shapes itself to its container.

Gases at ordinary pressure are very dilute: the molecules themselves constitute only about one-thousandth of the total volume of the gas, therest being empty space. Thus, 1 g of solid iodine has a volume of about 0.2 cm³ (its density is 4.93 g/cm³), where as 1 g of iodine gas at 1-atm pressure and at the temperature of 184°C (its boiling point) has a volume of 148 cm³, over 700 times greater. The volume of all the molecules in a gas at ordinary pressure is accordingly small compared with the volume of the gas itself. On the other hand, the diameter of a gas molecule is not extremely sniall compared with the distance between molecules; in a gas at room temperature and 1-atm pressure the average distance from a molecule to its nearest neighbours is about ten times its molecular diameter.

Mashq 3. Matnning asosiy tarkibini bir nechta jumlalarda ko'rsating.

Mashq 4. Matnning rejasini tuzing.

Mashq 5. Jumlalarni o'qing va matn mazmuniga mos kelishini ayting. Agar yo'q bo'lsa, ularni tuzating.

1. Molecules of a gas move freely in a volume of its container. 2. The Van dcr Waals forces don’t act between the molecules of a gas. 3. The molecules of a gas are rather elose together at ordinary pressure. 4. The volume occupicd by a gas is considerably greater than the volume of a solid of the same element. 5. The distance between the molecules of a gas at 1 -atm pressure is greater than the diameter of the molecule itself. 6. The temperature has no influence on the gas volume.

Mashq 6. Gazning eng o'ziga xos xususiyatlarini tavsiflovchi rus tilidagi jumlalarni qidiring va tarjima qiling.