Identify the correct statement .

Options

A. Non-conventional sources of energy cause more pollution
B. Ozone is a harmless gas present in the atmosphere
C. Chlorofluorocarbons break down to chlorine atoms by ultraviolet radiation.
D. Trees don not help in decreasing rate of global warming.

Explanation

To solve the question "Identify the correct statement," we will analyze each option one by one and determine which statement is accurate.

### Step-by-Step Solution:

1. **Evaluate Option 1:**
- Statement: "Non-conventional sources of energy cause more pollution."
- Analysis: Non-conventional sources of energy, such as wind and solar energy, are renewable and typically produce less pollution compared to conventional sources like fossil fuels. Therefore, this statement is incorrect.

2. **Evaluate Option 2:**
- Statement: "Ozone is a harmless gas present in the atmosphere."
- Analysis: Ozone (O₃) in the stratosphere protects us from harmful UV radiation, but at ground level, it is a harmful pollutant and can cause respiratory issues. Thus, this statement is also incorrect.

3. **Evaluate Option 3:**
- Statement: "Chlorofluorocarbons break down to chlorine atoms by ultraviolet radiation."
- Analysis: Chlorofluorocarbons (CFCs) do indeed break down in the presence of ultraviolet (UV) radiation, releasing chlorine atoms. These chlorine atoms can then react with ozone (O₃) and contribute to ozone depletion. This statement is correct.

4. **Evaluate Option 4:**
- Statement: "Trees do not help in decreasing the rate of global warming."
- Analysis: Trees absorb carbon dioxide (CO₂) during photosynthesis, which helps reduce the concentration of this greenhouse gas in the atmosphere. Therefore, this statement is also incorrect.

### Conclusion:
After evaluating all the options, the correct statement is **Option 3: "Chlorofluorocarbons break down to chlorine atoms by ultraviolet radiation."**

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