Which is the right structure of `XeF_4` ?

Options

A.
B.
C.
D.

Explanation

To determine the correct structure of \( \text{XeF}_4 \), we can follow these steps:

### Step 1: Determine the Valence Electrons
- **Xenon (Xe)** is a noble gas and has 8 valence electrons.
- Each **Fluorine (F)** atom contributes 1 valence electron, and since there are 4 fluorine atoms, they contribute a total of \( 4 \times 1 = 4 \) valence electrons.
- Total valence electrons = \( 8 + 4 = 12 \) electrons.

### Step 2: Calculate the Steric Number
- The steric number is calculated using the formula:
\[ \text{Steric Number} = \frac{1}{2} \left( \text{Valence Electrons of Central Atom} + \text{Number of Monovalent Atoms} - \text{Cationic Charge} + \text{Anionic Charge} \right) \]
- Here, the central atom is xenon (Xe), which has 8 valence electrons, and there are 4 fluorine atoms (monovalent).
- Plugging in the values:
\[ \text{Steric Number} = \frac{1}{2} \left( 8 + 4 + 0 + 0 \right) = \frac{1}{2} \times 12 = 6 \]

### Step 3: Determine the Geometry
- According to VSEPR theory, a steric number of 6 indicates an **octahedral** geometry.
- However, we need to account for the presence of lone pairs.

### Step 4: Identify Bonding and Lone Pairs
- In \( \text{XeF}_4 \):
- There are 4 bonding pairs (from the 4 Xe-F bonds).
- The remaining 2 electrons (from the total of 12) are lone pairs on the xenon atom.
- Thus, we have:
- Bonding pairs = 4
- Lone pairs = 2

### Step 5: Determine the Molecular Shape
- With 4 bonding pairs and 2 lone pairs, the molecular geometry is derived from the octahedral arrangement.
- The lone pairs will occupy positions opposite each other to minimize repulsion, resulting in a **square planar** shape for the bonding pairs.

### Step 6: Final Structure
- The final structure of \( \text{XeF}_4 \) is **square planar** with the fluorine atoms in the same plane and the lone pairs positioned above and below the plane.

### Conclusion
The correct structure of \( \text{XeF}_4 \) is square planar.

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