Following are neutral oxides except :

Options

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

Explanation

To solve the question of which oxides are neutral and which is not, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Neutral Oxides**:
- Neutral oxides are oxides that do not exhibit acidic or basic properties. They do not react with acids or bases and do not form salts when they do react.

2. **Identify the Given Oxides**:
- The oxides mentioned in the question are NO (nitric oxide), N2O (dinitrogen oxide), CO (carbon monoxide), and NO2 (nitrogen dioxide).

3. **Analyze Each Oxide**:
- **NO (Nitric Oxide)**: This is a neutral oxide. It does not react with acids or bases.
- **N2O (Dinitrogen Oxide)**: This is also a neutral oxide. It does not exhibit acidic or basic properties.
- **CO (Carbon Monoxide)**: This is another neutral oxide. It does not react with acids or bases.
- **NO2 (Nitrogen Dioxide)**: This oxide is not neutral. It reacts with water to form nitric acid (HNO3), indicating that it has acidic properties.

4. **Conclusion**:
- Among the given options, NO2 is the only oxide that is not a neutral oxide. Therefore, the answer to the question is NO2.

### Final Answer:
The oxide that is not a neutral oxide is **NO2 (Nitrogen Dioxide)**.

---