Lakhmir Singh Manjit Kaur Class 8 Science 18th Chapter Pollution Of Air And Water

Lakhmir Singh and Manjit Kaur Science solution: Pollution Of Air And Water Chapter 18. Here you get easy solutions of Lakhmir Singh and Manjit Kaur Science solution Chapter 18 . Here we give Chapter 18 all solution of Class 8. Its help you to complete your homework.

Board – CBSE

Text Book – SCIENCE

Class – 8

Chapter – 18


1) Carbon dioxide

2) Sulpher Dioxide, Nitrogen.

3) Carbon monoxide, nitrogen, Sulpher,

4) carbon monoxide.

5) Carbon dioxide, carbon monoxide etc.

6) Ozone gas.

7) Cholera, Diarrhea.

8) Mercury, Lead, Arsenic etc.

9) Fertilizers, Pesticides.

10) Nitrogen and phosphorus.


11) Ganga action plan is an ambitious plan to cleanse the highly polluted river ganga and reduce the pollution level in the water of river ganga.

It was launched in 1985

12) Four pollutant are Untreated sewage from homes, pesticides, Fertilizers, Industrial wastages.

The ways to controlling water pollution are :

  • Sewage should be treated properly at sewage treatment plants.
  • Farmers should use correct amounts of fertilizers and pesticides.
  • Garbage should not be thrown into open drains.

13) Industry create a lot of dangerous wastage and these wastages are dropped direct into the rivers.

14) The ways to reduce air pollution are :

  • The air pollution can be controlled by using smokeless fuels.
  • The air pollution from motor vehicles can be reduced by using CNG.
  • Can be controlled by using non-polluting sources of energy.

15) Pure air means there is no harmful gases in the air, Polluted air means there is contains harmful gases in the air.

16) The warming up of the earth’s atmosphere due to the trapping of sun’s heat rays by carbon dioxide gas in the atmosphere is called greenhouse effect.

17) Two greenhouse gases are carbon dioxide and carbon monoxide.

Carbon dioxide produces the maximum greenhouse effect.

18) CFC depletes the ozone layer in the atmosphere.

The dangerous UV rays will enter the earth and it will be harmful for living beings.

19) a> Burning of fossil fuel.  B> From Industry…. C> From vehicles .. d> From refrigerator.

20) Because it may still contain harmful micro organisms.

21) Because hot water is harmful for the living beings in the river.

22) The increased level of nutrients can increase the growth of algae in water and it will reduce the oxygen supply to the living beings in the water.

23) Toxic Chemicals in pesticides dissolves in rain water and run water, lakes and ponds. These pesticides kill aquatic animals like fish etc.

24) Air Pollution around the Taj Mahal is discolouring its marble also corroding it slowly , this poses a threat to the beauty of Taj Mahal.

The two ways to controlling air pollution :

  • The air pollution can be controlled by smokeless fuel.
  • Using CNG gas.

25) The water which is safe for drinking is called portable water.

Two methods to make water safe are : Boiling and Filter the water.


26) The contamination of water , rivers, lakes and ponds with unwanted and harmful substances is called water pollution.

The different ways of water pollution are :

  • Untreated sewage from homes.
  • Fertilizers used in agriculture.
  • Pesticides used in agriculture.

The harmful effect of water pollution are :

  • Drinking of water polluted with untreated sewage can cause disease such as cholera, typhoid etc.
  • Water of rivers and lakes polluted with pesticides can kill aquatic animals

27) Air is a mixture of gas. The various constituents are Oxygen, Nitrogen, carbon dioxide etc.

The contamination of air with harmful gases , smoke and dust is called air pollution.

The main sources of air pollution are – Carbon dioxide, carbon monoxide, sulphur dioxide etc.

28) Smog is a deadly air pollutant which is formed by the combination of smoke and smog.

The atmospheric pollutants or gases that form smog are released in the air when fuels are burnt. When sunlight and its heat react with these gases and fine particles in the atmosphere, smog is formed.

The harmful effect of smog are Cough and aggravates asthma and other lung diseases.

29) Acid rain is that rain which contains small amounts of acids formed from acidic gases like sulphur dioxide and nitrogen oxides present in polluted air.

The harmful effects of Acid rain are – Destroys forests,

kill aquatic animals Corrodes the statues, buildings etc.

30) The undue rise in the temperature of earth atmosphere due to excessive gree

Greenhouse effect produced by increasing amounts of carbon dioxide gas in the atmosphere is called global warming.

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  1. Nice and short questins

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