Among the following, the species which has the lowest value of bond angle is :

Options

A. `NO_(2)^(-)`
B. `NO_(2)`
C. `NO_(2)^(+)`
D. `N_(2)O`

Explanation

To determine which species has the lowest bond angle among the given options, we will analyze the molecular geometry and hybridization of each species.

### Step-by-Step Solution:

1. **Identify the Given Species**:
The species mentioned in the problem are NO2, N2O, O2-, and N+.

2. **Analyze NO2**:
- **Valence Electrons**: Nitrogen (N) has 5 valence electrons, and each Oxygen (O) has 6 valence electrons.
- **Total Valence Electrons**: 5 + (2 × 6) = 17 electrons.
- **Lewis Structure**: N forms one double bond with one O and a single bond with the other O. This results in one lone electron on nitrogen.
- **Steric Number**: 2 bond pairs + 1 lone pair = 3.
- **Hybridization**: sp².
- **Geometry**: Bent shape due to the lone pair, with a bond angle of approximately 115°.

3. **Analyze N2O**:
- **Valence Electrons**: 5 (N) + 5 (N) + 6 (O) = 16 electrons.
- **Lewis Structure**: N forms a triple bond with one N and a single bond with O.
- **Steric Number**: 2 bond pairs = 2.
- **Hybridization**: sp.
- **Geometry**: Linear, with a bond angle of 180°.

4. **Analyze O2-**:
- **Valence Electrons**: 6 (O) + 6 (O) + 1 (extra electron due to -2 charge) = 13 electrons.
- **Lewis Structure**: O forms a double bond with another O and has 2 lone pairs.
- **Steric Number**: 2 bond pairs + 2 lone pairs = 4.
- **Hybridization**: sp³.
- **Geometry**: Bent shape, with a bond angle of less than 109.5°.

5. **Analyze N+**:
- **Valence Electrons**: 5 (N) - 1 (due to +1 charge) = 4 electrons.
- **Lewis Structure**: N forms two bonds with O.
- **Steric Number**: 2 bond pairs = 2.
- **Hybridization**: sp.
- **Geometry**: Linear, with a bond angle of 180°.

6. **Comparison of Bond Angles**:
- NO2: 115°
- N2O: 180°
- O2-: Less than 109.5°
- N+: 180°

7. **Conclusion**:
The species with the lowest bond angle is **O2-**, which has a bond angle of less than 109.5°.

### Final Answer:
The species which has the lowest value of bond angle is **O2-**.