Correct Answer:
C. chlorine
Chlorofluorocarbons (CFCs) are synthetic organic compounds that were widely used as refrigerants and propellants. When CFCs reach the stratosphere, they are broken down by ultraviolet (UV) radiation, releasing highly reactive atoms. Among the components of CFCs, chlorine atoms are the primary culprits in ozone layer depletion. A single chlorine atom can catalytically destroy thousands of ozone molecules before it is removed from the stratosphere.
- Fluorine, while present in CFCs, is less reactive and does not significantly contribute to ozone depletion compared to chlorine.
- Bromine is also an ozone-depleting substance, found in halons (bromofluorocarbons), but the question specifically asks about CFCs and the most damaging gas within them.
- Therefore, 'None of these' is incorrect as chlorine is the correct answer.
The Montreal Protocol was established to phase out CFCs due to their detrimental impact on the ozone layer.