Chlorofluorocarbon deplete the ozone layer .

Answer

### Step-by-Step Solution:

1. **Understanding Chlorofluorocarbons (CFCs)**:
- Chlorofluorocarbons are chemical compounds that contain chlorine, fluorine, carbon, and hydrogen. They were commonly used in refrigeration, air conditioning, and aerosol propellants.

2. **Release of Chlorine**:
- When CFCs are released into the atmosphere, they eventually reach the stratosphere, where they are broken down by ultraviolet (UV) radiation. This breakdown releases chlorine atoms.

3. **Chlorine's Reaction with Ozone**:
- The released chlorine atoms are highly reactive and can react with ozone (O₃) molecules. The reaction can be summarized as follows:
\[ \text{Cl} + \text{O}_3 \rightarrow \text{ClO} + \text{O}_2 \]
- In this reaction, one chlorine atom reacts with an ozone molecule, resulting in the formation of chlorine monoxide (ClO) and diatomic oxygen (O₂).

4. **Destruction of Ozone**:
- The chlorine monoxide (ClO) can further react with a free oxygen atom (O) to release the chlorine atom back into the atmosphere:
\[ \text{ClO} + \text{O} \rightarrow \text{Cl} + \text{O}_2 \]
- This means that one chlorine atom can destroy many ozone molecules, leading to significant depletion of the ozone layer.

5. **Conclusion**:
- The overall process shows that chlorofluorocarbons contribute to ozone layer depletion by releasing chlorine, which reacts with ozone and breaks it down into oxygen molecules, thus reducing the concentration of ozone in the stratosphere.