Page 115 - ICSE Chemistry 6

4. ___________ are the substances that are burnt to release energy.
5. ___________________ is a process by which plants make their own food.
6. ______________ and ____________________ are examples of natural pollu on source.

B. Iden fy the error in the given statements. Circle the incorrect word and write the correct word in
the blank.
1. Air is made up of nearly 21% nitrogen. _______________

2. Nitrogen supports combus on. _______________
3. Oxygen is used in fi re ex nguishers. _______________
4. Dry wood releases carbon dioxide and hydrogen on burning. _______________
5. Photosynthesis is carried out by green plants because they contain a
green-coloured pigment called chloroplast. _______________
6. Ozone layer present in the earth’s biosphere protects us from harmful
ultraviolet (UV) rays. _______________

C. Choose the correct op on.
1. Which of the following gases is not a component of air?

(a) Oxygen (b) Sulphur (c) Nitrogen (d) Carbon dioxide
2. Which of the following is used as a refrigerant?
(a) Nitrogen (b) Sulphur (c) Water vapour (d) Carbon dioxide
3. How are water vapour formed?
(a) Due to boiling (b) Due to evapora on
(c) Due to boiling and evapora on (d) None of these

4. What are the by-products of respira on?
(a) Carbon dioxide and water (b) Oxygen and water
(c) Nitrogen and carbon dioxide (d) Oxygen and nitrogen
5. Which of the following is a clean fuel?
(a) LPG (b) Coal (c) Petrol (d) CNG

6. Which of the following is/are cause(s) of air pollu on?
(a) Burning of fossil fuels (b) Emissions from vehicles
(c) Release of chemicals by industries and factories
(d) All of these

D. Match the columns.
Column A Column B

1. Air (a) Cooking
2. Leguminous plants (b) Greenhouse gas
3. Dry wood (c) Reduce air pollu on
4. Coal (d) Mixture of gases
5. Methane (e) Fuel in power sta ons

6. Organic farming (f) Nitrogen fi xa on

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