The main factor of depletion of ozone layer is:

Options

A. chlorofluorocarbons
B. oxygen
C. sulphur
D. nitrogen

Explanation

**Step-by-Step Solution:**

1. **Identify the Ozone Layer**: The ozone layer is a region of Earth's stratosphere that contains a high concentration of ozone (O3) molecules. It plays a crucial role in protecting life on Earth by absorbing the majority of the sun's harmful ultraviolet (UV) radiation.

2. **Understand Ozone Depletion**: Ozone depletion refers to the thinning of the ozone layer, which leads to an increase in UV radiation reaching the Earth's surface. This can cause various environmental and health issues, including skin cancer and cataracts.

3. **Recognize the Main Culprit**: The primary substances responsible for ozone layer depletion are chlorofluorocarbons (CFCs). These are man-made compounds that were commonly used in refrigeration, air conditioning, and aerosol propellants.

4. **Mechanism of Depletion**: When CFCs are released into the atmosphere, they eventually rise to the stratosphere. There, they are broken down by UV radiation, releasing chlorine atoms. These chlorine atoms react with ozone (O3), leading to the formation of oxygen (O2) and depleting the ozone layer.

5. **Conclusion**: The main factor contributing to the depletion of the ozone layer is the release of chlorofluorocarbons (CFCs) into the atmosphere.

**Final Answer**: The main factor of depletion of the ozone layer is chlorofluorocarbons (CFCs).

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