Diamagnetic species are those which contain no unapired electrons. Which among the following are diagmagnetic?

Options

A. `N_(2)`
B. `N_(2)^(2-)`
C. `F_(2)^(+)`
D. `O_(2)^(-)`

Explanation

To determine which species are diamagnetic, we need to analyze their electronic configurations and check for the presence of unpaired electrons. Let's go through the options step by step.

### Step 1: Analyze N2 (Nitrogen)
1. **Total Electrons**: N2 has 14 electrons (7 from each nitrogen atom).
2. **Molecular Orbital Configuration**:
- σ1s²
- σ*1s²
- σ2s²
- σ*2s²
- π2p_x²
- π2p_y²
- σ2p_z²
3. **Filling Order**:
- Fill the 1s and 2s orbitals first (4 electrons).
- Then fill the 2p orbitals (2 in π2p_x, 2 in π2p_y, and 2 in σ2p_z).
4. **Result**: All orbitals are filled with no unpaired electrons.
5. **Conclusion**: N2 is diamagnetic.

### Step 2: Analyze O2 (Oxygen)
1. **Total Electrons**: O2 has 16 electrons (8 from each oxygen atom).
2. **Molecular Orbital Configuration**:
- σ1s²
- σ*1s²
- σ2s²
- σ*2s²
- π2p_x²
- π2p_y²
- π*2p_x¹
- π*2p_y¹
3. **Filling Order**:
- Fill the 1s and 2s orbitals first (4 electrons).
- Then fill the 2p orbitals (2 in π2p_x, 2 in π2p_y).
- Finally, place the remaining 2 electrons in the π* orbitals (1 in each).
4. **Result**: There are unpaired electrons in the π* orbitals.
5. **Conclusion**: O2 is paramagnetic.

### Step 3: Analyze F2+ (Fluorine cation)
1. **Total Electrons**: F2+ has 17 electrons (18 in F2 minus 1).
2. **Molecular Orbital Configuration**:
- σ1s²
- σ*1s²
- σ2s²
- σ*2s²
- π2p_x²
- π2p_y²
- π*2p_x¹
- π*2p_y¹
3. **Filling Order**:
- Fill the 1s and 2s orbitals first (4 electrons).
- Then fill the 2p orbitals (2 in π2p_x, 2 in π2p_y).
- Place the remaining electron in one of the π* orbitals.
4. **Result**: There is one unpaired electron.
5. **Conclusion**: F2+ is paramagnetic.

### Step 4: Analyze O2- (Oxygen anion)
1. **Total Electrons**: O2- has 18 electrons (16 in O2 plus 2).
2. **Molecular Orbital Configuration**:
- σ1s²
- σ*1s²
- σ2s²
- σ*2s²
- π2p_x²
- π2p_y²
- π*2p_x²
- π*2p_y¹
3. **Filling Order**:
- Fill the 1s and 2s orbitals first (4 electrons).
- Then fill the 2p orbitals (2 in π2p_x, 2 in π2p_y).
- Finally, fill the π* orbitals (2 in π*2p_x, 1 in π*2p_y).
4. **Result**: There is one unpaired electron in the π* orbitals.
5. **Conclusion**: O2- is paramagnetic.

### Final Conclusion
Among the species analyzed, only N2 is diamagnetic (no unpaired electrons). The other species (O2, F2+, and O2-) are paramagnetic (have unpaired electrons).

### Summary of Results
- **Diamagnetic**: N2
- **Paramagnetic**: O2, F2+, O2-