Question

Which of the following statements about the depletion of the ozone layer is correct?
A. Oxides of nitrogen also do not react with ozone in the stratosphere.
B. The problem of ozone depletion is less serious at poles because $N{O}_2$ solidifies and is not available for consuming $ClO$ radicals.
C. The problem of ozone depletion is more serious at poles because ice crystals in the clouds over poles act as catalyst for photochemical reactions involving the decomposition of ozone by $Cl$ and $ClO$ radicals
D. Freons, chlorofluorocarbons, are inert chemically, they do not react with ozone in the stratosphere.

Answer 1

Hint:In the spring season, however, the sun comes out, which provides the radiation for photochemical reactions to occur and melt the polar stratospheric clouds, and releases a considerable amount of $ClO$, which drives the whole mechanism.

Complete step by step answer:
The role of sunlight in ozone depletion is the reason why the pole depletion is greatest during the spring. At the winter time when the PSCs are at their most available, there is an absence sunlight reaching over the pole to drive chemical reactions. . As warm, ozone and $NO$ rich air flows in from the lesser elevation areas, the PSCs are destroyed and as a result, the natural process of ozone depletion shuts down, so the ozone hole closes. Ozone layer depletion causes increased UV radiation levels at the Earth's surface, which is dangerous for human health. Negative effects of ozone layer depletion consist of increasing in harmful to human diseases like eye cataracts, cancer of skin and immune deficiency disorders. UV rays also affect the growth of plants, reducing agricultural productivity all over the world.
Human activities cause ozone layer depletion and global warming. Ozone depletion occurs when the chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerators used at homes and restaurants are released into the atmosphere and thus causing harmful effects.

So from the above options the correct reason for ozone layer depletion is option c and so it is the correct answer.

Note: Ozone depletion is the gradual thinning of Earth's ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from the industries and other social activities. The thinning is most pronounced in the polar regions, especially over Antarctica.