OBJECTIVE TYPE QUESTIONS 

Question 1. Fill in the blanks:  (with Solutions)

1. Water is a matter because it has mas and occupies space.
2. Any matter which has a definite volume but no definite shape is called a liquid.
3. Fluid can flow.
4. The molecules are at a greater distance in gases compared to liquids.
5. Water boils at 100 °C.
6. The physical state of a substance, which has a fixed volume but no fixed shape is liquid.
7. All matter is made up of tiny particles called atoms.
8. Liquids have a definite Volume.
9. The temperature at which a liquid boils is called the boiling point of that liquids 
10. Molecules in a solid are packed very closely.
11. Liquids have no definite shape.
12. When a gas is cooled, its molecules loose energy,
13. Matter is anything that has mass and occupies space. 

Question 2. 

1. Write whether the following statements are true or false.
   • Only water can exist in three different states.
   • If the container in which a gas is collected has an opening, the gas will flow out and spread itself indefinitely.
   • Solids have the largest inter-molecular space.
   • There is no difference between evaporation and boiling.
   • All solids, on heating, first change to the liquid and then to the gaseous state always.
   • The inter molecular force of attraction is the weakest in gases.
   • A gas has no free surface.
   • Inter molecular force of attraction is greater in gases than in liquids.

Answer: 

(a) True (b) True (c) False (d) False (e) False (f) True (g) True (h) False. 

1. Write true or false for each statement. Rewrite the false statements correctly.
   • Matter cannot exist in different states.
   • If the inter molecular space is more than the inter molecular force will be weaker.
   • Solids and liquids can flow.
   • Solids can be compressed easily.
   • The smallest part of an ^element capable of independent existence is called an atom.
   • The inter molecular space in a gas is almost negligible.

Answer: (a) False. Matter can exist in different states. (b) True. (c) False. Gases and liquids can flow. (d) False. Solids cannot be compressed easily. (e) True (f) False. The inter molecular space in a gas is very large. 

Question 3. For each of the following statements, say whether it describes a solid, a liquid or a gas.

(a) Particles move about very quickly Liquid

(b) Particles are quite close together Solid

(c) Particles are far apart and move in all directions Gas 

Question 4. Name the phenomenon which causes the following changes: 

• • Formation of water vapour from water is vaporation.
  • Disappearance of camphor is sublimation.
  • Conversion of ice into water is melting.
  • Conversion of water into steam is boiling. 

Question 6. Give two examples for each of the following :

(a) Substances which sublime. Naphthalene, camphor, dry ice. 

(b) Substances which do not change their states. Paper, sugar. 

(c) Substances which are rigid and not compressible. Glass, stone, pen.