Assignment - Matter in our Surrounding, Class 9, Science PDF Download

FILL IN THE BLANKS :–

1. Density is measured in .............
2. The change of a liquid into vapour is called .............
3. The matter in our surrounding exists in three states .............,.............. and ............. –
4. Matter is made up of very small .............
5. The change of a solid directly into gas is called .............
6. Smell of cooked food reaches us in seconds due to the process known as .............
7. Intermolecular space in solids is ............. than that of liquids.
8. ............. have definite volume but not definite shape.
9. Rapid evaporation depends on the ............. area exposed to atmosphere.
10. Intermolecular forces of attraction are ............. in solids, ............. in liquids and ............. in gases.
11. Boiling point of water is ............. K and melting point of ice is ............. K.
12. 1 atm is equal to .............
13. Change of vapour state to liquid state is called .............
14. The best evidence that the particles of matter are constantly moving comes from the studies of ............. and ............. and .............
15. Plasma is a mixture of ............. and .............

WRITE T FOR TRUE AND F FOR FALSE STATEMENT :–
1. Air, water, chair, table and smell are examples of matter.
2. Gases have highest rate of diffustoin among all the three states of matter.
3. Evaporation causes heating.
4. Camphor changes to gaseous state without changing into liquid.
5. Water has boiling point equal to 100°C.
6. Evaporation is a bulk phenomenon.
7. Intermolecular forces are maximum in solids and minimum in gases.
8. Condensing is opposite to evaporating and freezing is opposite to melting.
9. The large volumes of gases can be put into small volumes of cylinders because of their property known
as compressibility.
10. Increase in humidity is out of the factor which increases the rate of evaporation.

ANSWER KEY:

Fill in the blanks
1. Kilogram per cubic meter

2. Vaporization

3. Solid, liquid and gas
4. Particles

5. Sublimation

6. Diffusion
7. Less

8. Liquids

9. Surface
10. Maximum, intermediate, minimum

11. 373, 273
12. 1.01 × 105 Pa

13. Condensation

14. Diffusion, brownian, motion
15. Free electrons and ions.

True (T), False (F)
1. F

2. F

3. F

4. T

5. T

6. F

7. T

8. T

9. T

10. F