Assertion : Ozone is destroyed by `CFCs` in the upper stratosphere.
Reason : Ozone holes increase the amount of `UV` radiation reaching the earth.

Options

A. Assertion and reason are incorrect Assertion and reason are both correct.
B.
Assertion and reason are correct, but and the reason is the correct explanation for the assertion.
C. the rason is not the explanation for the assertions.
D. Assertion is false, but the reason is correct.

Answer

To solve the question, we need to analyze the assertion and the reason provided:

**Assertion:** Ozone is destroyed by CFCs in the upper stratosphere.

**Reason:** Ozone holes increase the amount of UV radiation reaching the earth.

### Step-by-Step Solution:

1. **Understanding Ozone and CFCs:**
- Ozone (O₃) is a molecule that forms a protective layer in the stratosphere, absorbing harmful ultraviolet (UV) radiation from the sun.
- Chlorofluorocarbons (CFCs) are man-made compounds that contain chlorine, fluorine, and carbon. They are known to be harmful to the ozone layer.

**Hint:** Recall the structure and function of ozone in the atmosphere.

2. **Mechanism of Ozone Destruction:**
- When CFCs reach the upper stratosphere, they are broken down by UV radiation, releasing chlorine radicals (Cl).
- These chlorine radicals react with ozone, leading to its depletion. The reaction can be summarized as:
- Cl + O₃ → ClO + O₂
- ClO + O₃ → Cl + 2O₂
- This results in the conversion of ozone (O₃) into oxygen (O₂), effectively reducing the ozone concentration.

**Hint:** Consider the chemical reactions involved in ozone depletion by CFCs.

3. **Understanding Ozone Holes:**
- Ozone holes refer to areas where the concentration of ozone is significantly reduced, primarily observed over Antarctica.
- The depletion of ozone leads to an increase in the amount of UV radiation that reaches the Earth's surface, which can have harmful effects on living organisms.

**Hint:** Think about the consequences of reduced ozone levels on UV radiation exposure.

4. **Evaluating the Reason:**
- The reason states that ozone holes increase the amount of UV radiation reaching the Earth, which is true.
- However, the reason does not directly explain why CFCs destroy ozone. It merely states a consequence of ozone depletion.

**Hint:** Distinguish between a cause (CFCs destroying ozone) and an effect (increased UV radiation due to ozone holes).

5. **Conclusion:**
- The assertion is true: CFCs do destroy ozone in the upper stratosphere.
- The reason is also true: Ozone holes do increase UV radiation reaching the Earth.
- However, the reason does not correctly explain the assertion. Therefore, while both statements are true, the reason is not the correct explanation for the assertion.

### Final Answer:
- Assertion is true, but the reason is not the correct explanation for the assertion.