Chapter 18 Pollution Of Air And Water

Question 1. Air is a mixture of various gases. One of the gases is 21% part of the air and is essential for the survival of human beings. This gas is

(a) nitrogen

(b) oxygen

(c) ozone

(d) argon

Question 2. Which of the following is not a source of air pollution?

(a) automobile exhaust

(b) burning of firewood

(c) windmill

(d) power plant

Question 3. Boojho wishes to contribute in reducing air pollution. Which vehicle should he use for going to school?

(a) car

(b) school bus

(c) autorickshaw

(d) scooter

Question 4. Which of the following is not a way to conserve water?

(a) replace

(b) reduce

(c) reuse

(d) recycle

Question 5. The type of pollution which is likely to affect Taj Mahal in Agra to a greater extent is

(a) air pollution

(b) water pollution

(c) soil pollution

(d) noise pollution

Question 6. Incomplete combustion of fuel such as petrol and diesel gives

(a) nitrogen oxide

(b) sulphur dioxide

(c) carbon monoxide

(d) carbon dioxide

Question 7. The phenomenon of marble cancer is due to

(a) soot particles

(b) CFCs

(c) fog

(d) acid rain

Question 8. Potable water is the water which is

(a) obtained from a river.

(b) obtained from a lake.

(c) pure and fit for drinking.

(d) used only for washing clothes.

Question 9. Which of the following procedures will give you water free from all impurities?

(a) adding chlorine tablets

(b) distillation

(c) boiling

(d) filtration

Question 10. A pond contains clean water. Which of the following activities will produce least pollution of water?

(a) washing clothes in the pond

(b) animals bathing in the pond

(c) washing motor vehicles in the pond

(d) swimming in the pond.

Question 11. Trees help in reducing the pollution of our environment. Lakhs of trees are planted by people in the month of July every year. The occasion is called

(a) forest Conservation Day

(b) plantation month

(c) Van Mahotsav

(d) wildlife week

Question 12. Which of the following is not a green house gas?

(a) nitrogen gas

(b) water vapour

(c) methane gas

(d) carbon dioxide

Question 13. Name the chemicals which are used in refrigerators and air conditioners and damage ozone layer when released in air.

Question 14. Name any two sources which cause air pollution due to suspended particulate matter.

Question 15. Name two gases which are mainly responsible for acid rain?

Question 16. The quality of air at various locations is monitored regularly by government and other agencies? In what way can you use these data?

Question 17. Combustion of fossil fuels generates a lot of air pollution. Can you suggest any two alternative sources of energy which do not cause any pollution?

Question 18. Name any two water pollutants which are toxic for plants and animals.

Question 19. A lot of dry leaves are collected in a school garden and are burnt every day. Do you think that it is right to do so? If not, what should be done to dispose off the dry leaves?

Question 20. The level of air pollution is higher at a busy traffic intersection. Why?

Question 21. Fill in the blanks with the help of words given in bracket after each sentence.

(a) When air is contaminated by ________ substances which have a ________ effect on both the ________ and ________, it is referred to as ________.

(air pollution, harmful, living, unwanted, non-living, pollutants).

(b) Many ________ are responsible for causing ________ pollution. Petroleum ________ are a major source of ________ pollutants like ________ and ________.

(sulphur dioxide, refineries, industries, nitrogen dioxide, gaseous, liquid, people, air).

(c) While ________ your teeth, leaving the ________ running may waste several ________ of water.

(tap, litres, brushing, washing, drops)

(d) Water which is suitable for _________ is called ________ water.

(washing, bathing, drinking, potable, soft).

(e) Water which looks clean still has disease carrying ________ and ________ impurities.

(insects, microorganism, particles, dissolved, harmful).

Question 22. Match the items of Column A with those of Column B.

Question 23. Find out the wrong statements and write them in their correct form.

(a) We can survive for some time without air but we cannot survive even for a few minutes without food.

(b) A brick kiln emits lot of smoke and other harmful gases causing air pollution.

(c) Carbon monoxide is produced by complete burning of fuels such as coal, petrol, diesel.

(d) Chlorination is a commonly used chemical method for killing germs in water.

(e) Water which is suitable for drinking is called soft water.

Question 24. In the following statements, the underlined words are jumbled up. Write them in their correct form.

(a) Air contains 78% ginroten and 21% gonexy.

(b) Vehicles produce high level of pollutants like carbon dioxide, nitrogen oxides, nobrac moondexi and mosek.

(c) Carbon dioxide, thaneme, nitrous oxide and water vapour are known as heengrouse sesga.

(d) Gangotri glacier in Himalaya has started melting because of lablog ringwam.

(e) Whenever harmful substances such as wagese, toxic chemicals, silt, etc. get mixed with water, the water becomes potdulle.

Question 25. What do CFCs stand for? Name some devices where CFCs are used. Why CFCs are considered as pollutants?

Question 26. Why is it advised that industries should switch over to cleaner fuels such as CNG and LPG in the Taj Mahal Zone in Agra?

Question 27. It is said, “$CO_2$ contributes to global warming.” Explain.

Question 28. We should plant trees and nurture the ones already present in the neighbourhood. Why?

Question 29. Explain the traditional way of purifying water to make it fit for drinking.

Question 30. How can we reduce, reuse and recycle water?

Question 31. Read the paragraph and answer the questions following it.

Water is essential for life. Without water there would be no life. We usually take water as granted for its purity, but we must ensure the quality of water. Pollution of water originates from human activities. Through different paths, pollution reaches to ground water. Easily identified source or place of pollution is called as point source, e.g.– municipal and industrial discharge pipes, where pollutants enter the water source. Non–point sources of pollution are those where a source of pollution can not be easily identified, e.g.– agricultural run off, acid rain etc.

(i) How do you classify the various sources of water pollution?

(ii) What are the point sources of water pollution?

(iii) Name any two non-point sources of water pollution?

Question 32. Complete the crossword puzzle with the help of clues given below:

Across

1. Pollutant which was used in refrigerators and air conditioners. (18)

3. Produced on incomplete combustion of fuels. (14)

6. This chemical protects our crops and is washed into water bodies from the field. (9)

Down

2. This layer protects us from harmful ultraviolet rays. (5)

4. It is essential for combustion. (6)

5. Disease which is caused by drinking contaminated water. (7)

7. River which is famous in India and sustains most of the northern, central and eastern Indian population. (5)