Photochemical smog consists of

Options

A. `O_(3), SO_(2)` and hydrocarbons
B. `O_(3),PAN` and `NO_(2)`
C. `SO_(2),CO_(2)` and hydrocarbons
D. `SO_(2)`,PAN and smoke

Answer

**Step-by-Step Solution:**

1. **Understanding Photochemical Smog:**
- Photochemical smog is a type of air pollution that occurs when sunlight reacts with primary pollutants in the atmosphere.

2. **Identifying Primary Pollutants:**
- The primary pollutants involved in the formation of photochemical smog include volatile organic compounds (VOCs), nitrogen oxides (NOx), and sulfur oxides (SOx). These pollutants are emitted from various sources such as vehicle exhaust, industrial emissions, and other combustion processes.

3. **Chemical Reactions:**
- Under the influence of sunlight, these primary pollutants undergo chemical reactions. For example, nitrogen oxides and volatile organic compounds react in the presence of sunlight to produce secondary pollutants.

4. **Formation of Secondary Pollutants:**
- The key secondary pollutants formed during this process include:
- Ozone (O3)
- Peroxyacetyl Nitrate (PAN)
- Nitrogen Dioxide (NO2)

5. **Conclusion:**
- Therefore, photochemical smog consists of the following components:
- Ozone (O3)
- Peroxyacetyl Nitrate (PAN)
- Nitrogen Dioxide (NO2)

6. **Final Answer:**
- The correct option is: O3, PAN, and NO2.

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