Which of the following elements form `p pi- dpi` bonding in its oxide ?

Options

A. Lithium
B. Boron
C. Sulphur
D. Nitrogen

Explanation

To solve the question of which element forms `p pi - d pi` bonding in its oxide, we will analyze each of the given options step by step.

### Step 1: Understanding p pi - d pi Bonding
- **Definition**: A p pi - d pi bond involves the sidewise overlap of a p orbital from one atom and a d orbital from another atom. This type of bonding requires the presence of d orbitals in one of the bonding elements.

### Step 2: Analyzing Each Element
1. **Lithium (Li)**:
- Lithium is in the second period of the periodic table.
- Its electronic configuration is 1s² 2s¹.
- **Conclusion**: Lithium does not have d orbitals available for bonding. Therefore, lithium oxide cannot form p pi - d pi bonding.

**Hint**: Remember that elements in the second period do not have d orbitals.

2. **Boron (B)**:
- Boron is also in the second period.
- Its electronic configuration is 1s² 2s² 2p¹.
- **Conclusion**: Like lithium, boron lacks d orbitals. Therefore, boron oxide cannot form p pi - d pi bonding.

**Hint**: Check the period of the element; second-period elements lack d orbitals.

3. **Sulfur (S)**:
- Sulfur is in the third period.
- Its electronic configuration is [Ne] 3s² 3p⁴.
- **Analysis**: In compounds like SO₃, sulfur can undergo hybridization and promote electrons to the empty d orbitals, allowing it to form multiple bonds with oxygen.
- **Conclusion**: Sulfur can form p pi - d pi bonds in its oxides due to the presence of empty d orbitals.

**Hint**: Look for elements in higher periods (like the third) that can utilize d orbitals.

4. **Nitrogen (N)**:
- Nitrogen is in the second period.
- Its electronic configuration is 1s² 2s² 2p³.
- **Conclusion**: Nitrogen does not have d orbitals available for bonding. Therefore, nitrogen oxide cannot form p pi - d pi bonding.

**Hint**: Again, remember that second-period elements lack d orbitals.

### Step 3: Final Conclusion
After analyzing all four elements, we find that:
- **Lithium**: No p pi - d pi bonding.
- **Boron**: No p pi - d pi bonding.
- **Sulfur**: Forms p pi - d pi bonding in its oxides.
- **Nitrogen**: No p pi - d pi bonding.

Thus, the only element that forms p pi - d pi bonding in its oxide is **Sulfur**.

### Answer: Sulfur (S) forms p pi - d pi bonding in its oxide.