Which oxide of nitrogen act as a pollutant ?

Options

A. `N_(2)O_(5)`
B. NO
C. `NO_(2)`
D. `N_(2)O`

Answer

### Step-by-Step Solution:

1. **Identify the Oxides of Nitrogen**: The primary oxides of nitrogen include Nitric Oxide (NO), Nitrogen Dioxide (NO2), and Nitrous Oxide (N2O).

2. **Determine the Pollutant**: Among these oxides, Nitrogen Dioxide (NO2) is recognized as a significant pollutant. It is an irritant gas that can cause inflammation in the respiratory system when present in high concentrations.

3. **Analyze the Effects of NO2**: High levels of NO2 can lead to serious health issues, including respiratory problems and increased susceptibility to infections.

4. **Consider Other Nitrogen Oxides**: While NO2 is the most notable pollutant, Nitric Oxide (NO) and Nitrous Oxide (N2O) can also have harmful effects. NO can lead to lung infections and exacerbate conditions like asthma. N2O can cause irritation in the eyes, nose, and throat.

5. **Conclude the Answer**: Therefore, the oxides of nitrogen that act as pollutants are Nitrogen Dioxide (NO2), Nitric Oxide (NO), and Nitrous Oxide (N2O).

### Final Answer:
The oxides of nitrogen that act as pollutants are **NO (Nitric Oxide), NO2 (Nitrogen Dioxide), and N2O (Nitrous Oxide)**.

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