Which of the following species have one unpaired electron each

Options

A. `O_2, O_2^-`
B. `O_2, O_2^+`
C. `O_2^+, O_2^-`
D. `O_2^+, O_2^(2-)`

Explanation

To determine which of the given species have one unpaired electron each, we will analyze the molecular orbital (MO) configurations of the species involved: O2, O2^-, and O2^+.

### Step-by-Step Solution:

1. **Identify the Molecular Orbital Configuration for O2**:
- The molecular orbital configuration for O2 (dioxygen) is:
\[ \sigma_{1s}^2 \sigma_{1s}^{*2} \sigma_{2s}^2 \sigma_{2s}^{*2} \sigma_{2p_z}^2 \pi_{2p_x}^1 \pi_{2p_y}^1 \]
- In this configuration, O2 has a total of 2 unpaired electrons in the π orbitals (π2p_x and π2p_y).

2. **Determine the Molecular Orbital Configuration for O2^- (Oxygen anion)**:
- For O2^-, we add one more electron to the configuration of O2:
\[ \sigma_{1s}^2 \sigma_{1s}^{*2} \sigma_{2s}^2 \sigma_{2s}^{*2} \sigma_{2p_z}^2 \pi_{2p_x}^2 \pi_{2p_y}^1 \]
- In this case, one of the π electrons pairs up, resulting in only 1 unpaired electron in the π2p_y orbital.

3. **Determine the Molecular Orbital Configuration for O2^+ (Oxygen cation)**:
- For O2^+, we remove one electron from the configuration of O2:
\[ \sigma_{1s}^2 \sigma_{1s}^{*2} \sigma_{2s}^2 \sigma_{2s}^{*2} \sigma_{2p_z}^2 \pi_{2p_x}^1 \pi_{2p_y}^1 \]
- In this case, we still have 1 unpaired electron in the π2p_x orbital.

4. **Summary of Unpaired Electrons**:
- O2: 2 unpaired electrons
- O2^-: 1 unpaired electron
- O2^+: 1 unpaired electron

5. **Identify the Correct Options**:
- Now we check the options provided:
- Option A: O2 and O2^- (not correct, O2 has 2 unpaired electrons)
- Option B: O2 and O2^+ (not correct, O2 has 2 unpaired electrons)
- Option C: O2^+ and O2^- (correct, both have 1 unpaired electron)
- Option D: O2^+ and O2^- (duplicate, same as C)

### Conclusion:
The species that have one unpaired electron each are O2^+ and O2^-.