Which of the following property have been changed when all the oxygen atoms are replaced by fluorine atoms from `XeO_(3)` without changing the covalency of xenon?

Options

A. Oxidation state of xenon
B. Total number of lone pairs
C. Hybridisation of Xe in molecule
D. Shape of molecule

Explanation

To solve the question regarding the change in properties when all the oxygen atoms in `XeO3` are replaced by fluorine atoms to form `XeF6`, we will analyze the changes in hybridization, geometry, and oxidation state.

### Step-by-Step Solution:

1. **Identify the structure of `XeO3`:**
- `XeO3` has a central xenon atom bonded to three oxygen atoms.
- The covalency of xenon in `XeO3` is 4 (it forms 3 sigma bonds with oxygen and has one lone pair).
- The hybridization of `XeO3` is `sp³`, and its geometry is trigonal pyramidal due to the presence of one lone pair.

2. **Determine the structure of `XeF6`:**
- When all the oxygen atoms are replaced by fluorine atoms, we get `XeF6`.
- Fluorine has a valency of 1, and since we want to maintain the covalency of xenon, we can form 6 bonds with fluorine.
- This means xenon will now have 6 bond pairs and no lone pairs.

3. **Analyze the hybridization and geometry of `XeF6`:**
- With 6 bond pairs and no lone pairs, the steric number becomes 6.
- The hybridization for `XeF6` is `sp³d²`, which corresponds to a geometry of octahedral.

4. **Determine the oxidation state of xenon in both compounds:**
- In `XeO3`, the oxidation state of xenon can be calculated as follows:
- Let the oxidation state of xenon be \( x \).
- The total charge of the molecule is 0, and since each oxygen is -2, we have:
\[ x + 3(-2) = 0 \implies x - 6 = 0 \implies x = +6 \]
- In `XeF6`, the oxidation state of xenon is calculated similarly:
- Each fluorine is -1, so:
\[ x + 6(-1) = 0 \implies x - 6 = 0 \implies x = +6 \]

5. **Summarize the changes in properties:**
- **Hybridization:** Changes from `sp³` in `XeO3` to `sp³d²` in `XeF6`.
- **Geometry:** Changes from trigonal pyramidal in `XeO3` to octahedral in `XeF6`.
- **Oxidation State:** Remains +6 in both `XeO3` and `XeF6`.

### Conclusion:
When all the oxygen atoms in `XeO3` are replaced by fluorine atoms to form `XeF6`, the properties that change are the hybridization and geometry, while the oxidation state of xenon remains the same.