The bonds not present in diborane are

Options

A. B-H
B. B-H-B
C. B-B
D. H-B-H

Answer

To determine the bonds that are not present in diborane (B2H6), we need to analyze its structure and the types of bonds formed within the molecule.

### Step-by-Step Solution:

1. **Understanding the Structure of Diborane (B2H6)**:
- Diborane consists of two boron (B) atoms and six hydrogen (H) atoms.
- The molecular formula is B2H6.

2. **Identifying the Types of Bonds**:
- In diborane, there are two types of bonding:
- **Terminal Bonds**: Each boron atom is bonded to two hydrogen atoms through two-center two-electron bonds (B-H).
- **Bridge Bonds**: The two boron atoms are connected by two hydrogen atoms through three-center two-electron bonds (B-H-B).

3. **Analyzing the Given Options**:
- The options provided are:
- BH
- BHB
- BB
- HBH
- We need to identify which of these bonds are present or absent in diborane.

4. **Evaluating Each Bond**:
- **BH Bond**: Present (Boron is bonded to Hydrogen).
- **BHB Bond**: Present (This represents the bridging bond between the two boron atoms with hydrogen).
- **BB Bond**: Not Present (There is no direct bond between the two boron atoms; they are connected through hydrogen).
- **HBH Bond**: Present (This represents the terminal hydrogen bonds).

5. **Conclusion**:
- The bond that is not present in diborane is the **BB bond**.

### Final Answer:
The bond not present in diborane is **BB**.

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