Assertion : `XeF_(4)` is square planar
Reason :Xe atom in `XeF_(4)` is `dsp^(2)` hybridised

Options

A. If both (A) and (R ) are correct and (R ) is the correct explanation of (A)
B. If both (A) and (R ) are correct,but (R ) is the correct explanation of (A)
C. If (A) is correct but (R ) is incorrect
D. If (A) is incorrect but (R ) is correct

Explanation

To solve the given assertion and reason question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that `XeF4` is square planar. To verify this, we need to determine the molecular geometry of `XeF4`.

1. **Determine the Valence Electrons**:
- Xenon (Xe) has 8 valence electrons.
- Each fluorine (F) contributes 1 valence electron, and since there are 4 fluorine atoms, they contribute 4 electrons.
- Total valence electrons = 8 (from Xe) + 4 (from 4 F) = 12 valence electrons.

2. **Calculate the Steric Number**:
- The steric number is calculated using the formula:
\[ \text{Steric Number} = \frac{\text{Number of Valence Electrons} + \text{Number of Monovalent Atoms}}{2} \]
- Here, the number of monovalent atoms (F) = 4.
- Therefore, the steric number = \(\frac{12}{2} = 6\).

3. **Determine the Hybridization**:
- A steric number of 6 corresponds to `sp^3d^2` hybridization (not `dsp^2`).

4. **Molecular Geometry**:
- With `sp^3d^2` hybridization and 4 bonded pairs (from 4 F atoms) and 2 lone pairs on the Xe atom, the molecular geometry is square planar.

### Conclusion for Assertion:
- The assertion that `XeF4` is square planar is **correct**.

### Step 2: Analyze the Reason
The reason states that the Xe atom in `XeF4` is `dsp^2` hybridized.

1. **Check the Hybridization**:
- As calculated earlier, the hybridization for `XeF4` is `sp^3d^2`, not `dsp^2`.
- `dsp^2` hybridization corresponds to a steric number of 4, which does not apply here.

### Conclusion for Reason:
- The reason that the Xe atom in `XeF4` is `dsp^2` hybridized is **incorrect**.

### Final Conclusion:
- The assertion is correct, but the reason is incorrect.

### Summary:
- **Assertion**: `XeF4` is square planar - **Correct**
- **Reason**: Xe atom in `XeF4` is `dsp^2` hybridized - **Incorrect**