CBSE Class 7 Science Water A Precious Recourse Worksheet

ACTIVITY- 16.1 

Question 1- Name three activities by which water is being wasted?
Answer- Cleaning of houses and animals, washing car and opening tap during brushing our teeth.

Question 2- Should we check the wastage of water and why?
Answer- Yes, because there are very limited sources of fresh water on earth.

Question 1- ________ is the process by which water is converted from its liquid state to a gaseous state.
Answer- Evaporation. 

Question 2- ________ is the process by which water is converted from its gaseous state to a liquid state.
Answer- Condensation.

ACTIVITY- 16.2 

Question 1- Which beaker represents the underground water?
Answer- Beaker ‘C’.

Question 2- Which beaker represents the surface water?
Answer- Water remained in beaker ‘A’.

EXERCISE

1- Fill In The Blanks :

(i) The water we drink is in liquid state.
(ii) The process of seeping of water into the soil is called infiltration.
(iii) The upper level of ground water is called water-table.
(iv) Water management means dealing with water in the best possible ways.
(v) A farmer can use water economically in the field, by drip irrigation.

2- Write True Or False.

(i) Water cycle helps in maintaining water on the earth. (True)
(ii) About 97% of total water present on the earth is fresh water. (False)
(iii) Repair leaking taps and pipes at the earliest. (True)
(iv) We are quickly moving towards global water crisis. (True)
(v) Turn on taps while brushing. (False)

3- Match The Column:-
Column I                        Column II
(i) Ice                       (a) Oceans and sea
(ii) Saline water         (b) Rivers and ponds
(iii) Fresh water         (c) Gaseous state of water
(iv) Water vapour      (d) Purest form of water
(v) Rain water           (e) Solid state of water
Ans-(i)-e,(ii)-a,(iii)-b,(iv)-c,(v)-d

4. Choose One Option For The Follwing.

Question. Which of the following is responsible for depletion of ground water?
a) Increasing population 1
b) Increasing industries
c) Deforestation
d) All of these 
Ans.d) All of these 

Question. The Punjab preservation of subsoil water act was passed in the year:
a) 2009
b) 2010
c) 200l
d) 2015
Ans.a) 2009

Question. The world water day is celebrated every year on:
a) 22 April
b) 24 March
c) 22 March
d) 22 May
Ans.c) 22 March

Question. Oceans and sea cover about ………. of the earth surface.
a) 75%
b) 71%
c) 97% 
d) 29%
Ans.c) 97%

Question. We should not keep taps running while:
a) Brushing
b) Shaving
c) Bathing
d) All of these
Ans.d) All of these

5- Very Short Answer Type Questions.

Question. What do you mean by ground water?
Answer- Groundwater is the water present below the earth’s surface in the cracks and spaces in soil, sand and rocks.

Question. Why is sea and ocean water not fit for drinking?
Answer- Because sea and ocean water have large amounts of dissolved salts.

Question. Define aquifers.
Answer- Groundwater present between the layers of hard rocks below the water table is known as aquifer.

Question. Name the three states of water.
Answer- Solid, liquid and gas.

Question. How is groundwater recharged?
Answer- Rainwater and water from other sources such as rivers and ponds seeps into the soil due to gravity until the empty spaces and cracks deep below the ground are filled with water. This process is known as infiltration. Hence groundwater gets recharged.

6- Short Answer Type Questions.

Question. Enlist some activities by which water is being wasted by people.
Answer- Water is being wasted by people in cleaning of houses and animals, washing car and opening taps during brushing teeth.

Question. How will you minimize the use of water to maintain a garden?
Answer- We should water the garden early in the morning and late afternoon taking shorter showers. We should reuse the waste water of cleaning purposes in watering the plants.

Question. How is water important to us?
Answer-
(1) About 70% of human body consists of water.
(2) Water helps to control our body temperature.
(3) Water helps to excrete waste products from our body.
(4) Water is important for growth of plants.
(5) Water maintains the temperature of earth.
(6) Water is essential for our many daily life activities.

Question. How increase in human population is leading to depletion of water table?
Answer- As the human population increase, consumption of water by them increases for their daily activities.Often groundwater is used for construction of houses, shops and roads etc. Hence groundwater is used at high rate, but the area for seepage of water decreases. So water table is depleted by growth in human population.

Question. Why do plants wilt and finally dry up if they do not get water for some days?
Answer- Plants use water in photosynthesis. Also plants lose some water by transpiration. So if plants do not get water for some days, they wilt and finally dry up.

7- Long Answer Type Questions.

(i) What steps will you take to save water?
Answer- (1) Make efforts to stop the leakage of water from taps and water pipes.
(2) Turn off taps while brushing or shaving.
(3) Mop the floor instead of washing, reuse the waste water to water the plants.
(4) Water the garden early in the morning and late afternoon taking shorter showers.
(5) Wash vegetables and fruits in big containers and use this water for cleaning or watering the plants.

More Question

I Fill in the blanks:

1. The ________________ in the soil indicates the presence of underground water.

2. Water in the aquifers can be usually pumped out with help of __________ or _______________.

3. _____________ was the traditional way of collecting water.

4. Shortage of ___________ has become a matter of concern.

II Write True or False:

1. Celebration of water day is to attract the attention of everybody towards the importance of conserving water.

2. 76% of the earth’s surface is covered with water.

3. Glaciers are the solid form of water.

4. Excessive rains cause droughts whereas the absence of rains results in floods.

III Define :

1. Drip irrigation.

IV Diagram:

Ground water and Water table.