In which of the following molecules/ions all the bond angles are not equal ?

Options

A. `SiF_4`
B. `IC l_4^(-)`
C. `SF_4`
D. `PCl_4^(-)`

Explanation

To determine which of the given molecules/ions has bond angles that are not equal, we will analyze each option step by step.

### Step 1: Analyze SiF4
1. **Determine the Valence Electrons**: Silicon (Si) has 4 valence electrons, and each fluorine (F) has 1 valence electron. Therefore, for SiF4:
- Valence electrons from Si = 4
- Valence electrons from 4 F = 4 × 1 = 4
- Total = 4 + 4 = 8 valence electrons.

2. **Calculate Hybridization**: Using the formula:
\[ \text{Hybridization} = \frac{1}{2} \left( V + M - C + A \right) \]
where \( V = 4 \) (Si), \( M = 4 \) (F), \( C = 0 \), \( A = 0 \):
\[ \text{Hybridization} = \frac{1}{2} (4 + 4) = \frac{8}{2} = 4 \quad \Rightarrow \quad \text{sp}^3 \]
- **Geometry**: Tetrahedral
- **Bond Angles**: All bond angles are equal (approximately 109.5°).