Question

Why is the concentration of ozone less over the north and south poles?

• A. CFC's accumulate only in area where the air is cold
• B. CFC use is highest in these areas
• C. CFC's stick to frozen water vapour and are able to act as catalysts
• D. UV rays are stronger in the atmosphere

Answer 1

Answer: (C)

The geographical location having low temperatures leads to the destruction of ozone present in the stratospheric locations. At these temperatures, clouds form in the lower stratosphere from the water vapour. CFCs allow the chemical reactions inside them to transform compounds derived from halocarbons into active compounds. These processes lead to the rapid destruction of ozone when sunlight returns over the pole. So, the concentration of ozone is less over the north pole and south pole.

Thus, the correct answer is option C.