Q1) Write true or false for each statement.
(a) The molecules of each substance are identical.
(b) The intermolecular forces are effective at all distances between the two molecules.
(c) The molecules in a substance are in random motion .
(d) In a gas, the molecules can move anywhere in space.
(e) The liquids are less viscous than the gases.
Q2) Fill in the blanks
(a) All the molecules of a substance are __________.
(b) The intermolecular spacing is _________in the solids, _________ in liquids and __________ in gases
(c) The molecular motion in liquid and gas is in zig zag path
(d) In a solid, the molecules __________. but they remain at their fixed positions.
(e) The intermolecular forces are the weakest in __________.
(f) A solid exerts pressure __________.
(g) The gases are least ______dense.
(h) A solid is _______ rigid.
Q3) Select the corect alternative:
(a) The diameter of a molecule is approximately
(b) The intermolecular forces are strongest in
Both (i) and (ii)
(c) The molecules
In solid, liquid and gas, move freely anywhere
In a solid, move freely within its boundary
In a liquid, move within its boundary
In a gas, move only within its boundary
(d) The solids are
(e) The intermolecular forces in liquids are
As strong as in solids
Stronger than in solids
Weaker than in solids
Weaker than in gases
Q4) Match the following columns :
|Column A||Column B|
|(a) A molecule is composed of||(i) does not exist free in nature|
|(b) Ice, water and water vapour||(ii) can vibrate [[> widget id="1" <]]m from their mean position|
|(c) An atom||(iii) atoms|
|(d) Gases||(iv) are the three states of water|
|(e) The molecules of a solid||(v) occupy space|
Q12) How do the solids , liquids and gases differ in their following properties.
Q14) Describe a simple experiment to illustrate that molecules are not at rest , but they constantly move.
Q16) Give the molecular model for a solid and use it to explain why a solid has a definite volume and a definite shape.
Q17) Describe the molecular model for a liquid. How does it explain that a liquid has no definite shape, but has a definite Volume ?
Q18) A gas has neither a definite volume nor a definite shape. Describe the molecular model to explain it.
Q19) Distinguish between the three states of matter - solid, liquid and gas on the basis of their molecular models.
Q20) Distinguish between solids, liquids and gases on the basis of their following properties :
(d) Expansion on heating
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