Which one of the following is resposible of depletion of ozone layer in the upper strate of the atmosphere ?

Options

A. polyhalogens
B. Ferrocene
C. Fullerences
D. Freons

Answer

**Step-by-Step Solution:**

1. **Understanding the Ozone Layer**: The ozone layer is located in the stratosphere, which is the second layer of the Earth's atmosphere. It plays a crucial role in absorbing the majority of the sun's harmful ultraviolet (UV) radiation.

2. **Identifying the Culprits**: The primary substances responsible for the depletion of the ozone layer are chlorofluorocarbons (CFCs). These compounds are commonly found in products like refrigerants, aerosol sprays, and foam-blowing agents.

3. **Mechanism of Ozone Depletion**: When CFCs are released into the atmosphere, they eventually rise up to the stratosphere. Here, they are broken down by UV radiation, releasing chlorine atoms.

4. **Chlorine's Role**: The free chlorine atoms react with ozone (O3) molecules. A chlorine atom can destroy thousands of ozone molecules before it is removed from the stratosphere. The reaction can be summarized as follows:
- A chlorine atom reacts with ozone to form chlorine monoxide (ClO) and oxygen (O2).
- The chlorine monoxide can then react with a free oxygen atom to release the chlorine atom again, allowing it to continue the cycle of ozone destruction.

5. **Conclusion**: The depletion of the ozone layer is primarily caused by chlorofluorocarbons (CFCs). Therefore, the correct answer to the question is CFCs.

**Final Answer**: Chlorofluorocarbons (CFCs) are responsible for the depletion of the ozone layer in the upper stratosphere of the atmosphere.

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