Among the oxides of nitrogen `N_(2)O, NO and NO_(2)`, molecules with unpaired electrons are:

Options

A. `N_(2)O and NO`
B. `NO and NO_(2)`
C. `N_(2)O and NO_(2)`
D. `NO_(2)` and Its dimer

Answer

To determine which of the nitrogen oxides \( N_2O \), \( NO \), and \( NO_2 \) have unpaired electrons, we can follow these steps:

### Step 1: Determine the total number of valence electrons for each molecule.
- **For \( N_2O \)**:
- Nitrogen (N) has 5 valence electrons, and there are 2 nitrogen atoms: \( 5 \times 2 = 10 \).
- Oxygen (O) has 6 valence electrons: \( 6 \).
- Total valence electrons = \( 10 + 6 = 16 \).

- **For \( NO \)**:
- Nitrogen (N) has 5 valence electrons: \( 5 \).
- Oxygen (O) has 6 valence electrons: \( 6 \).
- Total valence electrons = \( 5 + 6 = 11 \).

- **For \( NO_2 \)**:
- Nitrogen (N) has 5 valence electrons: \( 5 \).
- Oxygen (O) has 6 valence electrons, and there are 2 oxygen atoms: \( 6 \times 2 = 12 \).
- Total valence electrons = \( 5 + 12 = 17 \).

### Step 2: Check if the total number of valence electrons is odd or even.
- **For \( N_2O \)**: Total = 16 (even)
- **For \( NO \)**: Total = 11 (odd)
- **For \( NO_2 \)**: Total = 17 (odd)

### Step 3: Determine the presence of unpaired electrons.
- A molecule with an odd number of total valence electrons will have unpaired electrons.
- Since \( N_2O \) has an even number of valence electrons, it does not have unpaired electrons.
- Both \( NO \) and \( NO_2 \) have odd numbers of valence electrons, indicating they have unpaired electrons.

### Conclusion:
The molecules with unpaired electrons are \( NO \) and \( NO_2 \).

### Final Answer:
The molecules with unpaired electrons are \( NO \) and \( NO_2 \).

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