1. What is the main reason for using a digital balance in Activity 8.4?

2. The chapter concludes that states of water can be changed by:

3. Water is essential for survival of plants and animals.

4. List down the uses of water

5. Water is a good _______

6. The water present below the surface is called _______

7. Open source of water are

8. ________ and _______ are used to draw water from ground water.

9. Ocean water cannot be used for domestic purpose because it contains

10. How much of earth's surface is covered with water?