Which of the following is an odd electron molecule?

Options

A. `CO_2`
B. `SO_2`
C. `NO_2`
D. `Al_2O_3`

Answer

To determine which of the following is an odd electron molecule, we need to analyze the electron configurations and bonding of the given molecules. An odd electron molecule is characterized by having an unpaired electron, which means that the total number of valence electrons is odd.

### Step-by-Step Solution:

1. **Identify the Molecules**: First, we need to identify the molecules provided in the question. For this example, let's assume the options are:
- A) O2 (Oxygen)
- B) SO2 (Sulfur Dioxide)
- C) NO2 (Nitrogen Dioxide)
- D) H2O (Water)

2. **Count Valence Electrons**:
- **O2**: Each oxygen has 6 valence electrons, so for O2:
- Total = 6 + 6 = 12 (even)
- **SO2**: Sulfur has 6 valence electrons and each oxygen has 6:
- Total = 6 + 6 + 6 = 18 (even)
- **NO2**: Nitrogen has 5 valence electrons and each oxygen has 6:
- Total = 5 + 6 + 6 = 17 (odd)
- **H2O**: Each hydrogen has 1 valence electron and oxygen has 6:
- Total = 1 + 1 + 6 = 8 (even)

3. **Identify Odd Electron Molecule**: From our calculations:
- O2: 12 (even)
- SO2: 18 (even)
- NO2: 17 (odd)
- H2O: 8 (even)

The only molecule with an odd number of valence electrons is **NO2**.

4. **Conclusion**: Therefore, the odd electron molecule among the options is **NO2 (Nitrogen Dioxide)**.