The strength of bonds formed by overlapping of 2s-2s, 2p-2p and 2p-2s follows the order

Options

A. `2s-2s gt 2p-2p gt 2s-2p`
B. `2s-2sgt 2p-2s gt 2p-2p`
C. 2p-2pgt2s-2pgt 2s-2s
D. `2p-2p gt 2s-2s gt 2p-2s`

Answer

To determine the strength of bonds formed by the overlapping of 2s-2s, 2p-2p, and 2p-2s orbitals, we can analyze the nature of the overlaps based on the directional character and area of overlap of the orbitals involved.

### Step-by-Step Solution:

1. **Understanding Orbital Shapes**:
- The **2s orbital** has a spherical shape, which means it is **non-directional**.
- The **2p orbital** has a dumbbell shape, which gives it a **directional character**.

2. **Comparing Overlaps**:
- **2s-2s Overlap**:
- This involves two spherical orbitals overlapping. The area of overlap is small due to the non-directional nature of the s orbitals.
- **Strength**: Weakest bond strength due to minimal overlap.

- **2p-2s Overlap**:
- This involves one spherical (2s) and one directional (2p) orbital. The p orbital can orient in space, allowing for a better overlap compared to two s orbitals.
- **Strength**: Moderate bond strength due to some directional overlap.

- **2p-2p Overlap**:
- This involves two directional p orbitals. Both orbitals can orient themselves to maximize overlap, leading to a larger area of interaction.
- **Strength**: Strongest bond strength due to maximum overlap and directional character.

3. **Ranking the Bond Strengths**:
- Based on the analysis:
- **2p-2p** overlap has the strongest bond strength.
- **2p-2s** overlap has moderate bond strength.
- **2s-2s** overlap has the weakest bond strength.

4. **Final Order of Bond Strength**:
- The order of bond strength from strongest to weakest is:
- **2p-2p > 2p-2s > 2s-2s**.

### Conclusion:
The correct order of bond strength formed by overlapping of 2s-2s, 2p-2p, and 2p-2s is:
**2p-2p > 2p-2s > 2s-2s**.