Question

Which of the following is most harmful to the ozone layer?

• A. SO$_2$
• B. CO$_2$
• C. Freon
• D. All of these

Hint:

Freon, a type of CFC, is a major contributor to the depletion of the ozone layer, allowing more UV radiation to reach the Earth's surface.

Answer 1

The Correct Option is C

Step 1: Understand ozone depletion.
The ozone layer is depleted primarily by chlorine and bromine-containing compounds, notably chlorofluorocarbons (CFCs), commonly known as Freon.
Step 2: Review the options.
- SO$_2$ (Sulfur dioxide) contributes to acid rain but is not directly involved in ozone layer depletion.
- CO$_2$ (Carbon dioxide) contributes to global warming but does not affect the ozone layer significantly.
- Freon (CFCs) is the most harmful as it releases chlorine atoms, which break down ozone molecules.
- "All of these" is incorrect as only Freon is a significant ozone-depleting substance.
Step 3: Conclude.
Freon is the most harmful to the ozone layer, making option (C) the correct answer.
Final Answer: \[ \boxed{\text{Freon}} \]