Which will not cause atmospheric pollution ?

Options

A. `SO_(2)`
B. `CO_(2)`
C. CO
D. `H_(2)`.

Explanation

To determine which option does not cause atmospheric pollution, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Analyze Sulphur Dioxide (SO₂)**:
- Sulphur dioxide is a significant air pollutant.
- It is released from motor vehicle exhaust and industrial processes.
- It contributes to acid rain formation, which causes further environmental damage.
- **Conclusion**: Sulphur dioxide causes atmospheric pollution.

2. **Analyze Carbon Dioxide (CO₂)**:
- Carbon dioxide is a greenhouse gas essential for maintaining the Earth's temperature.
- It is used in photosynthesis by plants.
- However, when its concentration exceeds a certain threshold, it can lead to carbon dioxide poisoning and other health issues.
- **Conclusion**: Carbon dioxide can cause atmospheric pollution when present in high concentrations.

3. **Analyze Carbon Monoxide (CO)**:
- Carbon monoxide is produced from incomplete combustion of fossil fuels and motor vehicle exhaust.
- It is highly toxic and can lead to carbon monoxide poisoning, affecting oxygen transport in the body.
- **Conclusion**: Carbon monoxide is a significant atmospheric pollutant.

4. **Analyze Hydrogen (H₂)**:
- Hydrogen is a simple diatomic molecule and is not considered an atmospheric pollutant.
- It exists naturally in the atmosphere and does not have harmful effects when present in typical concentrations.
- When hydrogen reacts with oxygen, it forms water vapor, which is not a pollutant.
- **Conclusion**: Hydrogen does not cause atmospheric pollution.

### Final Answer:
The option that will not cause atmospheric pollution is **Hydrogen (H₂)**.

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