Question

The ozone layer is getting depleted because of:

• A. excessive use of automobiles
• B. excessive formation of industrial units
• C. excessive use of manmade compounds containing both fluorine and chlorine
• D. excessive deforestation

Answer 1

The correct option is C

excessive use of manmade compounds containing both fluorine and chlorine

The correct option is option C.

Explanation for Correct option:

1. The ozone layer, also called the stratosphere, is composed of the ozone gas (90% of the total ozone in the atmosphere).
2. The main cause of ozone depletion and the ozone hole is manufactured chemicals, especially manufactured halocarbon refrigerants, solvents, propellants, and foam- blowing agents (chlorofluorocarbons (CFCs), HCFCs, halons.
3. CFC molecules are made up of chlorine, fluorine and carbon atoms which are extremely stable.
4. This extreme stability allows CFC's to slowly make their way into the stratosphere (most molecules decompose before they can cross into the stratosphere from the troposphere).
5. This prolonged life in the atmosphere allows them to reach great altitudes where photons are more energetic.
6. When the CFC's come into contact with these high energy photons, their individual components are freed from the whole.

Explanation for Incorrect option:

Option A:

Although the pollutants released due to excessive use of automobiles degrade the ozone layer, it is not insignificant.

Option B:

The significance of degradation of the ozone layer due to excessive formation of industrial units is low.

Option D:

Deforestation does not affect the ozone layer directly but rather in an indirect way.

Final answer: Ozone layer is getting depleted because of excessive use of manmade compounds containing both fluorine and chlorine.