Which of the following is planar?

Options

A. `SiCl_4`
B. `NF_3`
C. `SF_4`
D. `XeF_4`

Explanation

To determine which of the given compounds is planar, we will calculate the steric number and hybridization for each compound and analyze their molecular geometries.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given are SiCl4, NF3, SF4, and XeF4.

2. **Calculate the Steric Number for each Compound**:
- **SiCl4**:
- Silicon (Si) has 4 valence electrons.
- There are 4 chlorine (Cl) atoms attached (monovalent).
- Steric Number = (Valence Electrons + Monovalent Atoms) / 2 = (4 + 4) / 2 = 4.
- Hybridization: sp³.
- Geometry: Tetrahedral (not planar).

- **NF3**:
- Nitrogen (N) has 5 valence electrons.
- There are 3 fluorine (F) atoms attached.
- Steric Number = (5 + 3) / 2 = 4.
- Hybridization: sp³.
- Geometry: Pyramidal (not planar due to lone pair).

- **SF4**:
- Sulfur (S) has 6 valence electrons.
- There are 4 fluorine (F) atoms attached.
- Steric Number = (6 + 4) / 2 = 5.
- Hybridization: sp³d.
- Geometry: Seesaw (not planar due to lone pair).

- **XeF4**:
- Xenon (Xe) has 8 valence electrons.
- There are 4 fluorine (F) atoms attached.
- Steric Number = (8 + 4) / 2 = 6.
- Hybridization: sp³d².
- Geometry: Square planar (planar).

3. **Conclusion**:
- Among the compounds analyzed, only **XeF4** has a planar geometry, specifically a square planar shape.

### Final Answer:
The planar compound is **XeF4**.