Class-6 Science Chapter-14 Water

 EVENTS CONVENT HIGH SCHOOL

05/02/2021             CLASS-6                   SLOT-2
Science
Chapter-14 Water

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1.Fill up the blanks of the following:-

(a) The process of changing of water into its vapour is called evaporation or vaporisation

(b) The process of changing water vapour into water is called condensation

(c) No rainfall for a year or more may lead to droughts in that region.

(d) Excessive rains may cause flood

 

2. State for each of the following whether it is due to evaporation or condensation:

(a) Water drops appear on the outer surface of a glass containing cold water. -condensation

(b) Steam rising from wet clothes while they are ironed. -evaporation

(c) Fog appearing on a cold winter morning. -condensation

(d) Blackboard dries up after wiping it. -evaporation

(e) Steam rising from a hot girdle when water is sprinkled on it. -evaporation

 

3. Which of the following statements are “true” Or “false’

(a) Water vapour is present in air only during the monsoon. False

(b) Water evaporates into air from oceans, rivers and lakes but not from the soil. False

(c) The process of water changing into its vapour is called evaporation. True

(d) The evaporation of water takes place only in sunlight. False

(e) Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler. True

 

VERY SHORT ANSWER TYPE QUESTIONS

 1. Write the sources of water on the earth.

Ans:  Sources of water on the earth are:

Seas, Oceans, Rivers, Springs, Tubewells, etc.

 2. In which forms, water exists on the earth?

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

 3. What is transpiration?

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

4. How are the clouds formed?

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

 5. What is meant by the conservation of water?

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

 
SHORT ANSWER TYPE QUESTIONS

 1. Mention two main functions of water for living organisms.

Ans: 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.

2. Why is ocean water not suitable for domestic use?

Ans: 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.

 3. Why does the water split on the floor disappear after some time?

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

 4. How does heavy rain affect us?

Ans: Heavy rains may cause:

1. A rise of water level in dams, rivers, lakes, etc.

2. Waterlogging and floods.

3. Floods cause damage to property, crops and animals.

 5. How does the failure of rainfall affect people on the earth?

Ans: The failure of rainfall can cause the following:

1.The soil becomes dry.

2. Water level in rivers, lakes, dams, etc. may fall. Ponds and canals may even dry up.

3. The ground water level falls.

 
6. Name two processes responsible for the formation of clouds.

Ans:  Evaporation and transpiration.

 7. During winters why do we see more fog in close areas where there are lots of .trees?

Ans:  Due to lots of trees, air at that place contains much more water vapour during winters. These vapour condense on dust or smoke particles forming thick fog.