Question 1

Which of the following is not a greenhouse gas?

Accepted Answer

A greenhouse gas is a gas that produces heat in the atmosphere as it increases. It also gets stuck in the environment and can not leave the internal layer of the Earth&#8217;s atmosphere. These gases introduce pollution because they contaminate the environment.Examples of greenhouse gases: Carbon dioxides, Methane, Chlorofluorocarbon, sulphur dioxide.Whereas oxygen, nitrogen, and argon are not examples of greenhouse gases.

Question 2

Which of the following is a secondary air pollutant?

Accepted Answer

A primary pollutant is an air pollutant emitted directly from a source.A secondary pollutant is not directly emitted as such, but forms when other pollutants (primary pollutants) react in the atmosphere.Examples of a secondary pollutant include ozone, which is formed when hydrocarbons ($HC$) and nitrogen oxides combine in the presence of sunlight. Nitrogen oxide which is formed as $NO$ combines with oxygen in the air; and acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water.

Question 3

Match the Column I and Column II and choose the correct code given below.Column IColumn II(A) Peroxyacetyl nitrile(i) Waste incineration(B) Indigo(ii) Vat dye(C) IR active molecules(iii) Global warming(D) Dioxins(iv) Photochemical smog

Accepted Answer

(A) Peroxyacetyl nitrate (PAN) is used in the photochemical smog.(B) Indigo is a vat dye. Dyeing with indignation was carried out in the wooden vats in the form of water-soluble indigo tin-white.(C) IR active molecules such as $CO_2, NO_X, SO_X$ are causing global warming.(D) Dioxins are used to burn the waste into ashes-Waste incineration.

Question 4

At an individual level, how can you help reduce air pollution?

Accepted Answer

Following steps can be taken to reduce air pollution at individual level:1. Use of bicycles more than the fuel based vehicles.2. Public transport can be used more than the private vehicles for commuting.3. Planting of saplings will provide a pollution free air in near future .4. Avoid burning leaves, trash, and other materials.5 Avoid using gas-powered lawn and garden equipment

Question 5

What are the different ways in which water gets contaminated?

Accepted Answer

Water gets contaminated by following:1. Untreated sewage.2. Practice of bathing and washing near a water body.3. Practice of cremating the dead bodies near river banks.4. Oil spill. 5.Throwing chemical waste into waters.6.Dumping agricultural waste into water.

Question 6

Which of the following is not a green house gas?

Accepted Answer

A greenhouse gas is a gas that produces heat in the atmosphere as it increases. It also gets stuck in the environment and can not leave the internal layer of the Earth&#8217;s atmosphere. These gases introduce pollution because they contaminate the environment.Examples of greenhouse gases are carbon dioxides, methane, CFC, sulphur dioxide.Whereas oxygen, nitrogen, and argon are not examples of greenhouse gases.

Question 7

Which of the following is not a source of air pollution?

Accepted Answer

Windmill are used to produce energy by the motion of wind, it is a renewable source of energy and does not cause air pollution.

Question 8

Explain the differences between pure air and polluted air.

Accepted Answer

Pure air Polluted air1. Pure air contains around 78% nitrogen, 21% oxygen and 0.03% carbon dioxide.1. Polluted air has no such definite composition of these gases.2. Other gases such as argon, methane, ozone, and water vapours  are also present in small quantities. 2. Polluted air has harmful gases like nitrogen dioxide, sulphur dioxide, carbon monoxide, particulate matter etc.3. It is fresh and healthy for lungs.   3. It can cause respiratory diseases.

Question 9

The phenomenon of marble cancer is due to:

Accepted Answer

Pollutants like sulphur dioxide and nitrogen dioxide in air react with water vapour present in the atmosphere to form sulphuric acid and nitric acid. These acids mix with rain, making it acidic. This acid rain corrodes building material like marble, and the phenomenon is called marble cancer. The other options, A, B, and C do not directly cause marble cancer.

Question 10

Why does the increased level of nutrients in the water affect the survival of aquatic organisms?

Accepted Answer

Eutrophication is when the environment becomes enriched with nutrients. It is a natural process in lakes, occurring as they age through geological time. It causes structural changes to the ecosystem such as increased production of algae and aquatic plants,  general deterioration water quality and other effects leading to the deficiency of oxygen in the water which affects the survival of aquatic organisms like fishes etc.