Question

Consider the following statements about ozone :
(a) Ozone is poisonous gas.
(b)Ozone shields the earth's surface from the infrared radiation from the sun.
(c) Ozone is a product of UV radiations acting on oxygen molecule.
(d) At the lower level of the earth's atmosphere, ozone performs most essential function.
The correct statements are

• (a) and (b)
• (a) and (c)
• (b) and (c)
• (b) and (d)

Answer 1

The Correct Option is B

Step 1: Understanding each statement about ozone:
(a) Ozone is a poisonous gas.
This statement is true. Ozone (O₃) is a toxic gas, and in high concentrations, it can be harmful to humans and animals. It can cause respiratory problems and irritation to the eyes and throat.

(b) Ozone shields the earth's surface from the infrared radiation from the sun.
This statement is false. Ozone primarily shields the Earth from ultraviolet (UV) radiation from the Sun, not infrared (IR) radiation. The Earth's atmosphere, particularly the ozone layer, absorbs and protects us from harmful UV rays, which can cause skin cancer and cataracts.

(c) Ozone is a product of UV radiations acting on oxygen molecules.
This statement is true. Ozone is formed when ultraviolet (UV) radiation from the Sun breaks apart oxygen molecules (O₂), leading to the formation of individual oxygen atoms (O). These atoms then combine with other O₂ molecules to form ozone (O₃). This process is called the ozone-oxygen cycle.

(d) At the lower level of the Earth's atmosphere, ozone performs most essential functions.
This statement is false. While ozone in the lower atmosphere (troposphere) contributes to air pollution and smog, its most essential functions occur in the upper atmosphere (stratosphere). In the stratosphere, ozone acts as a protective layer, shielding life on Earth from harmful UV radiation.

Step 2: Conclusion:
The correct statements are: - (a) Ozone is a poisonous gas. - (c) Ozone is a product of UV radiations acting on oxygen molecules.