The element of VI A group which cannot form hexahalides is

Options

A. O
B. S
C. Se
D. Te

Answer

To determine which element of Group VI A cannot form hexahalides, we will analyze the elements in this group: oxygen, sulfur, selenium, and tellurium.

### Step-by-Step Solution:

1. **Identify the Elements in Group VI A**:
- The elements in Group VI A (or Group 16) are oxygen (O), sulfur (S), selenium (Se), and tellurium (Te).

2. **Understand Hexahalides**:
- Hexahalides are compounds formed when an element bonds with six halogen atoms (e.g., fluorine, chlorine). The general formula for a hexahalide is X6, where X is the element.

3. **Analyze the Electronic Configuration**:
- Oxygen (O): Atomic number 8, electronic configuration is 1s² 2s² 2p⁴.
- Sulfur (S): Atomic number 16, electronic configuration is 1s² 2s² 2p⁶ 3s² 3p⁴.
- Selenium (Se): Atomic number 34, electronic configuration is [Ar] 3d¹⁰ 4s² 4p⁴.
- Tellurium (Te): Atomic number 52, electronic configuration is [Kr] 4d¹⁰ 5s² 5p⁴.

4. **Determine the Availability of D Orbitals**:
- Oxygen does not have any d orbitals available for bonding since it is in the second period.
- Sulfur has a 3d orbital but does not typically utilize it for bonding in hexahalides.
- Selenium and tellurium have d orbitals available and can utilize them for bonding.

5. **Conclusion**:
- Since oxygen lacks vacant d orbitals, it cannot form hexahalides. The other elements (sulfur, selenium, and tellurium) can form hexahalides because they have available d orbitals for bonding.

Thus, the element of Group VI A that cannot form hexahalides is **oxygen (O)**.