Acid rain happens because :

Options

A. sun leads to heating of upper layer of atmosphere
B. burning of fossil fuels release oxides of carbon, nitrogen and sulphur in the atmosphere
C. electrical charges are produced due to friction amongst clouds
D. the earth atmosphere contains acids

Explanation

### Step-by-Step Solution:

1. **Understanding Acid Rain**:
- Acid rain refers to precipitation (rain, snow, sleet, or hail) that has a lower pH than normal, making it acidic. This occurs when certain pollutants in the atmosphere mix with water vapor.

2. **Identifying Causes**:
- There are two main categories of causes for acid rain: **man-made (anthropogenic)** and **natural**.

3. **Man-Made Causes**:
- **Pollution from Industries**: Factories and power plants emit pollutants such as sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) into the atmosphere.
- **Burning of Fossil Fuels**: The combustion of coal, oil, and gas releases carbon dioxide (CO₂), sulfur dioxide (SO₂), and nitrogen oxides (NOₓ), which contribute to the formation of acid rain.

4. **Natural Causes**:
- **Volcanic Eruptions**: Natural events like volcanic eruptions release gases such as sulfur dioxide and other volcanic gases into the atmosphere, which can also lead to acid rain.
- **Other Natural Sources**: Lightning strikes and wildfires can also contribute to the formation of acid rain through the release of nitrogen oxides.

5. **Conclusion**:
- Acid rain occurs due to a combination of human activities that pollute the atmosphere and natural phenomena that release acidic gases. The main contributors are emissions from industries and volcanic eruptions.

### Final Answer:
Acid rain happens because of several human activities that pollute the atmosphere, such as the emission of carbon dioxide, sulfur, and nitrogen from industries and the burning of fossil fuels. Additionally, natural phenomena like volcanic eruptions also contribute to acid rain by releasing gases that form acidic clouds.

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