Which of the following molecules has one unpiared electron in antibonding orbitals ? .

Options

A. `CO`
B. `O_(2)^(Θ)`
C. `O_(2)^(o+)`
D. `NO`

Explanation

To determine which of the given molecules has one unpaired electron in antibonding orbitals, we will analyze each molecule step by step.

### Step 1: Identify the total number of electrons in each molecule.
- **CO (Carbon Monoxide)**:
- Carbon (C) has 6 electrons.
- Oxygen (O) has 8 electrons.
- Total = 6 (C) + 8 (O) = 14 electrons.

- **O2⁻ (Superoxide Ion)**:
- Each Oxygen (O) has 8 electrons, so 2 O atoms = 16 electrons.
- The negative charge adds 1 electron.
- Total = 16 + 1 = 17 electrons.

- **O2⁺ (Oxygen Cation)**:
- Each Oxygen (O) has 8 electrons, so 2 O atoms = 16 electrons.
- The positive charge removes 1 electron.
- Total = 16 - 1 = 15 electrons.

- **NO (Nitric Oxide)**:
- Nitrogen (N) has 7 electrons.
- Oxygen (O) has 8 electrons.
- Total = 7 (N) + 8 (O) = 15 electrons.

### Step 2: Determine the number of unpaired electrons based on the total number of electrons.
- **CO**:
- Total = 14 (even) → 0 unpaired electrons.

- **O2⁻**:
- Total = 17 (odd) → 1 unpaired electron.

- **O2⁺**:
- Total = 15 (odd) → 1 unpaired electron.

- **NO**:
- Total = 15 (odd) → 1 unpaired electron.

### Step 3: Conclusion
From the analysis, we find that:
- CO has 0 unpaired electrons.
- O2⁻ has 1 unpaired electron.
- O2⁺ has 1 unpaired electron.
- NO has 1 unpaired electron.

Thus, the molecules that have one unpaired electron in antibonding orbitals are **O2⁻, O2⁺, and NO**.

### Final Answer:
The correct options are **O2⁻, O2⁺, and NO**.

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