Chapter 1 – Natural Resources – Air, Water and Land
Time - 45 Minutes
Marks - 20
1. All the questions are compulsory.
2. Read the question paper carefully.
3. Marks are included against each question.
1. Fill in the blanks: (3 marks)
(a) The layer of ozone gas absorbs ______ rays that come from the sun to the earth.
(b) Of the total water available on the earth, fresh water forms ______ percent.
(c) Both ______ and ______ constituents are present in the soil.
2. Why is it said that? (2 marks)
Water is life.
3. Match the following. (2 marks)
Group ‘A’
(1) Carbon soil
(2) Oxygen
(3) Water vapour
(4) Microbes
Group ‘B’
(a) Generation of soil
(b) Rain
(c) Plants and food production
(d) Combustion
4. Name the following. (3 marks)
(a) Constituents of the biosphere
(b) Gases that are harmful to the ozone layer
(c) Inert gases in air
5. True or false? (2 marks)
(a) Land and soil are the same thing.
(b) It takes about 1000 years to form a 25 cm thick layer of soil.
6. Answer in your own words.
(a) Explain with the help of a diagram how soil is formed. (5 marks)
(b) Why is there a shortage of water even though it occupies about 71% of the earth’s surface? (2 marks)
(c) Why are air, water and land considered to be valuable natural resources? (1 mark)