Question

Which gas is primarily responsible for the depletion of the ozone layer?

• A. Carbon dioxide \((CO_2)\)
• B. Methane \((CH_4)\)
• C. Chlorofluorocarbons \((CFCs)\)
• D. Nitrogen oxides \((NO_x)\)

Hint:

CFCs release chlorine radicals in the stratosphere, which destroy ozone molecules.

Answer 1

The Correct Option is C

The ozone layer is present in the stratosphere. It protects the earth from harmful ultraviolet radiation. Chlorofluorocarbons are mainly responsible for ozone layer depletion. CFC molecules are stable in the lower atmosphere. When they reach the stratosphere, ultraviolet radiation breaks them and releases chlorine radicals. These chlorine radicals react with ozone: \[ O_3. \] They convert ozone into oxygen: \[ O_2. \] One chlorine radical can destroy many ozone molecules. Carbon dioxide and methane are mainly greenhouse gases. Nitrogen oxides may also affect atmospheric chemistry, but the primary gas group responsible for ozone depletion is CFCs. Therefore, the correct answer is: \[ \text{Chlorofluorocarbons }(CFCs). \]