The shapes of `SF_(4)andXeF_(2)` respectively are

Options

A. trigonal bipyramidal and trigonal bipyramidal
B. see -saw and linear
C. T- shape and linear
D. square planar and trigonal bipyramidal

Answer

To determine the shapes of SF4 and XeF2, we need to follow these steps:

### Step 1: Determine the Valence Electrons
- **For SF4**: Sulfur (S) has 6 valence electrons, and each Fluorine (F) has 7 valence electrons. Since there are 4 Fluorine atoms, the total is:
\[ \text{Total valence electrons} = 6 + (4 \times 7) = 6 + 28 = 34 \]

- **For XeF2**: Xenon (Xe) has 8 valence electrons, and each Fluorine (F) has 7 valence electrons. Since there are 2 Fluorine atoms, the total is:
\[ \text{Total valence electrons} = 8 + (2 \times 7) = 8 + 14 = 22 \]

### Step 2: Calculate the Steric Number
The steric number is calculated using the formula:
\[ \text{Steric Number} = \frac{\text{(Number of valence electrons on central atom)} + \text{(Number of attached atoms)} - \text{(Charge on cation)} + \text{(Charge on anion)}}{2} \]

- **For SF4**:
- Central atom: Sulfur (6 valence electrons)
- Number of attached atoms: 4 (Fluorine)
- Charge: 0
\[ \text{Steric Number} = \frac{6 + 4 + 0 + 0}{2} = \frac{10}{2} = 5 \]

- **For XeF2**:
- Central atom: Xenon (8 valence electrons)
- Number of attached atoms: 2 (Fluorine)
- Charge: 0
\[ \text{Steric Number} = \frac{8 + 2 + 0 + 0}{2} = \frac{10}{2} = 5 \]

### Step 3: Determine Hybridization
- **For both SF4 and XeF2**: A steric number of 5 corresponds to hybridization of sp³d.

### Step 4: Determine the Shape
- **For SF4**: With 4 bonded atoms and 1 lone pair, the molecular geometry is seesaw.

- **For XeF2**: With 2 bonded atoms and 3 lone pairs, the molecular geometry is linear.

### Conclusion
The shapes of SF4 and XeF2 are respectively:
- **SF4**: Seesaw
- **XeF2**: Linear

### Final Answer
The shapes of SF4 and XeF2 are **seesaw** and **linear**, respectively.

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