Science & Biotechnology

1. Which of the following is a greenhouse gas or a gas that can damage the ozone layer? [S.S.C. Online CHSL (T-I) 31.01.2017 (Shift-I)]

(a) SiF₄
(b) HCHO
(c) O₂
(d) CClF₃

Correct Answer: (d) CClF₃

Solution:CClF₃ or R-13 or CFC-13 is responsible for ozone depletion.

2. Which of the following is a greenhouse gas or a gas which can deplete the ozone layer? [S.S.C. Online CHSL (T-I) 31.01.2017 (Shift-I)]

(a) BCl₃
(b) Ni(CO)₄
(c) CH₃OH
(d) CClF₃

Correct Answer: (d) CClF₃

Solution:CClF₃ or R-13 or CFC-13 is responsible for ozone depletion.

3. Which of the following is a greenhouse gas or a gas which can deplete the ozone layer? [S.S.C. Online CHSL (T-I) 3.02.2017 (Shift-II)]

(a) BF₃
(b) O₂
(c) CHClF₂
(d) Cl₂

Correct Answer: (c) CHClF₂

Solution:CHClF₂, or R-22 gas, is also responsible for ozone depletion.

4. Which of the following is a greenhouse gas or a gas, which can deplete the ozone layer? [S.S.C. Online CHSL (T-I) 30.01.2017 (Shift-I)]

(a) AsH₃
(b) C₆H₆
(c) C₆H₄
(d) CH₄

Correct Answer: (d) CH₄

Solution:CH₄, methane gas, is responsible for the depletion of the ozone layer.

5. How many oxygen atoms are there in a molecule of ozone? [S.S.C. Online MTS (T-I) 12.10.2021 (Shift-III)]

(a) Three
(b) Two
(c) Four
(d) One

Correct Answer: (a) Three

Solution:Ozone gas (O₃) is the only allotrope of oxygen, one molecule of which is made up of three oxygen atoms.

6. Which of the following is NOT a greenhouse gas? [S.S.C. Online CGL (T-I) 17.08.2021 (Shift-I)]

(a) Helium
(b) Nitrous oxide
(c) Water vapor
(d) Surface level ozone

Correct Answer: (a) Helium

Solution:Helium is not a greenhouse gas. Greenhouse gases include carbon dioxide, methane, water vapor, nitrous oxide, and fluorinated gases. These gases are found naturally in the atmosphere.

7. What is the Greenhouse Effect? [S.S.C. Online MTS (T-I) 17.09.2017 (Shift-III)]

(a) turning green in the house due to being covered with algae
(b) turning green in the house due to the green component of white light
(c) heating of the earth by the radiation intercepted by the earth’s atmosphere
(d) none of these

Correct Answer: (c) heating of the earth by the radiation intercepted by the earth’s atmosphere

Solution:The greenhouse effect or greenhouse effect is the increase in the temperature of the earth and its surrounding atmosphere. This effect is caused by an increase in the number of certain gases in the atmosphere, which absorbs thermal rediation. For example CO2 water vapor, N2O methane, etc.

8. ___ gases trap heat in the atmosphere, which makes the Earth warmer, causing global warming. [S.S.C. Online Graduate Level (T-I) 12.06.2019 (Shift-III)]

(a) Elemental
(b) Compound
(c) Nobel
(d) Greenhouse

Correct Answer: (d) Greenhouse

Solution:Greenhouse gases (such as CO₂, water vapor, nitrous oxide, and chlorofluorocarbons) trap heat in the atmosphere, increasing the temperature of the Earth. This process is called global warming.

9. Which of the following destroys the ozone layer? [S.S.C. Online Graduate Level (T-I) 6.06.2019 (Shift-II)]

(a) Silicon
(b) Sulphur
(c) Carbon
(d) Chlorine

Correct Answer: (d) Chlorine

Solution:The chlorine present in chlorofluorocarbons or freon damages or destroys the ozone layer. Freon is a volatile gas used in industrial refrigerants and air conditioners that, upon reaching the atmosphere, releases chlorine from the effects of ultraviolet rays, which cause ozone depletion.

10. Which of the following pollutants is a secondary pollutant? [S.S.C. Online MTS (T-I) 21.08.2019 (Shift-I)]

(a) Ozone
(b) Nitrogen oxide
(c) Carbon monoxide
(d) Sulfur dioxide

Correct Answer: (a) Ozone

Solution:Secondary pollutants are not emitted directly from a source, as ozone (O₃) gas is a secondary pollutant. The gases that are produced directly from a source and enter the atmosphere as pollutants are primary pollutants. Gases such as nitrogen oxide (NOₓ), carbon monoxide (CO), and sulfur dioxide are the primary pollutants.