The correct bond order among the following species is :

Options

A. `N_(2)^(2-) gt N_(2)^(-) gt N_(2) gt N_(2)^(+)`
B. `N_(2) gt N_(2)^(-)=N_(2)^(+) gt N_(2)^(2-)`
C. `N_(2)^(2-) gt N_(2)^(+) gt N_(2)^(-) gt N_(2)`
D. `N_(2)^(-) gt N_(2) = N_(2)^(2-) >N_(2)^(+)`

Answer

To determine the correct bond order among the species N2, N2+, N2-, N2 2+, and N2 2-, we will calculate the bond order for each species step by step.

### Step 1: Calculate Bond Order for N2
1. **Determine the total number of electrons**:
- Each nitrogen atom has 7 electrons. For N2, the total number of electrons = 7 x 2 = 14 electrons.

2. **Write the molecular electronic configuration**:
- The configuration for N2 is:
- σ1s² σ*1s² σ2s² σ*2s² π2px² π2py² σ2pz² π*2px⁰ π*2py⁰ σ*2pz⁰

3. **Count the electrons in bonding and antibonding orbitals**:
- Bonding orbitals: σ1s (2) + σ2s (2) + π2px (2) + π2py (2) + σ2pz (2) = 10 electrons.
- Antibonding orbitals: σ*1s (2) + σ*2s (2) = 4 electrons.

4. **Calculate bond order**:
- Bond order = 1/2 (Number of bonding electrons - Number of antibonding electrons)
- Bond order = 1/2 (10 - 4) = 3.

### Step 2: Calculate Bond Order for N2+
1. **Determine the total number of electrons**:
- N2+ has one less electron, so total electrons = 14 - 1 = 13 electrons.

2. **Write the molecular electronic configuration**:
- The configuration for N2+ is:
- σ1s² σ*1s² σ2s² σ*2s² π2px² π2py² σ2pz¹ π*2px⁰ π*2py⁰

3. **Count the electrons in bonding and antibonding orbitals**:
- Bonding orbitals: 9 electrons (same as N2, but one less in σ2pz).
- Antibonding orbitals: 4 electrons.

4. **Calculate bond order**:
- Bond order = 1/2 (9 - 4) = 2.5.

### Step 3: Calculate Bond Order for N2-
1. **Determine the total number of electrons**:
- N2- has one extra electron, so total electrons = 14 + 1 = 15 electrons.

2. **Write the molecular electronic configuration**:
- The configuration for N2- is:
- σ1s² σ*1s² σ2s² σ*2s² π2px² π2py² σ2pz² π*2px¹ π*2py⁰

3. **Count the electrons in bonding and antibonding orbitals**:
- Bonding orbitals: 10 electrons (same as N2).
- Antibonding orbitals: 5 electrons.

4. **Calculate bond order**:
- Bond order = 1/2 (10 - 5) = 2.5.

### Step 4: Calculate Bond Order for N2 2+
1. **Determine the total number of electrons**:
- N2 2+ has two less electrons, so total electrons = 14 - 2 = 12 electrons.

2. **Write the molecular electronic configuration**:
- The configuration for N2 2+ is:
- σ1s² σ*1s² σ2s² σ*2s² π2px² π2py² σ2pz²

3. **Count the electrons in bonding and antibonding orbitals**:
- Bonding orbitals: 8 electrons.
- Antibonding orbitals: 4 electrons.

4. **Calculate bond order**:
- Bond order = 1/2 (8 - 4) = 2.

### Step 5: Calculate Bond Order for N2 2-
1. **Determine the total number of electrons**:
- N2 2- has two extra electrons, so total electrons = 14 + 2 = 16 electrons.

2. **Write the molecular electronic configuration**:
- The configuration for N2 2- is:
- σ1s² σ*1s² σ2s² σ*2s² π2px² π2py² σ2pz² π*2px¹ π*2py¹

3. **Count the electrons in bonding and antibonding orbitals**:
- Bonding orbitals: 10 electrons.
- Antibonding orbitals: 6 electrons.

4. **Calculate bond order**:
- Bond order = 1/2 (10 - 6) = 2.

### Summary of Bond Orders
- N2: Bond order = 3
- N2+: Bond order = 2.5
- N2-: Bond order = 2.5
- N2 2+: Bond order = 2
- N2 2-: Bond order = 2

### Final Bond Order Comparison
The bond order from highest to lowest is:
1. N2 (3)
2. N2+, N2- (2.5)
3. N2 2+, N2 2- (2)

### Conclusion
The correct order of bond order among the species is:
N2 > N2+, N2- > N2 2+, N2 2-.