CLASS - IX Science (Matter in our surrounding) work sheet

1. If you decrease the surface area and increase the temperature, then the rate of
evaporation
(a) increase (b) decrease (c) remain same
(d) may increase or decrease depending upon other factors

2. 300k will have its corresponding temperature in degree centigrade as:-
(a) 30 c (b) 300 c (c) 27  c (d) 673 c

3. Liquid to gas and gas to liquid changes are called:-
(a) vaporization and condensation (b) condensation and vaporization
(c) sublimation and condensation (d) condensation and sublimation

4. Physical state of water at 25 c, 0 c and 100 c is respectively
(a) liquid, solid and gas (b) solid, liquid and gas
(c) solid, gas and liquid (d) gas, solid and liquid

5. What happens when the temperature of the solids increase?

6. When heat is being supplied to a solid, then what does the heat energy do to the
particles of solid?

7. Why is it that on increasing the wind speed the rate of evaporation increases?

8. Why do we say that evaporation is a surface phenomenon?

9. What is the state of inter particle distance inside a solid, liquid and gas?

10. Why it is that to smell cold food, we have to go close but smell of hot food
reaches us several meters away?

11. Why is it that a wooden chair should be called a solid and not a liquid?

12. Give an experiment to show that ammonium chloride undergoes sublimation.