Explain the following:
Secondary pollutants

Explanation

### Step-by-Step Text Solution:

1. **Definition of Pollutants**:
- Pollutants are substances that cause pollution, which can harm the environment and living organisms.

2. **Understanding Secondary Pollutants**:
- Secondary pollutants are not emitted directly from a source. Instead, they form in the atmosphere through chemical reactions involving primary pollutants and other compounds.

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