NCERT 6th Class (CBSE) Science: Water and Its Importance

Question: In which forms, water exists on the earth?

Answer: Water exists on the earth in all three physical forms: ice, water and water vapour.

Question: What is transpiration?

Answer: Loss of water in the form of water vapour through stomata of leaves is called transpiration.

Question: How are the clouds formed?

Ans: Clouds are formed by the condensation of water vapour at high altitude.

Question: What is meant by the conservation of water?

Answer: Careful, economical and wise use of water and avoiding the wastage of water is called conservation of water.

Question: Mention two main functions of water for living organisms.

Answer: Two main functions of water for living organisms are:

1.  Water is essential for the germination of seeds, growth of plants and in photosynthesis.
2.  Water is used for the transportation of people and goods.

Question: Why is ocean water not suitable for domestic use?

Answer: Sea and ocean water contains large amounts of various salts. It is due to these salts the ocean water is salty and cannot be used for drinking, washing and for irrigation purposes.

Question: Why does the water split on the floor disappear after some time?

Answer: Due to evaporation the water split is changed into water vapour. So it disappears after some time.