The number of 2-centre-2-electron and 3-centre-2-electron bonds in `B_(2)H_(6)`, respectively, are

Options

A. 2 and 1
B. 4 and 2
C. 2 and 2
D. 2 and 4

Explanation

To determine the number of 2-centre-2-electron and 3-centre-2-electron bonds in diborane (B₂H₆), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of B₂H₆**:
- Diborane consists of two boron atoms and six hydrogen atoms. The molecular structure is such that the boron atoms are bonded to hydrogen atoms and also to each other.

2. **Hybridization of Boron**:
- Each boron atom in B₂H₆ undergoes sp³ hybridization, resulting in four hybrid orbitals. However, due to the presence of bridging hydrogen atoms, not all orbitals are used for bonding in the typical sense.

3. **Identifying 2-Centre-2-Electron Bonds**:
- A 2-centre-2-electron bond involves two atoms sharing a pair of electrons. In B₂H₆, each boron atom forms bonds with two terminal hydrogen atoms.
- Therefore, there are 4 2-centre-2-electron bonds (2 bonds from each boron to two different hydrogen atoms).

4. **Identifying 3-Centre-2-Electron Bonds**:
- A 3-centre-2-electron bond involves three atoms sharing a pair of electrons. In B₂H₆, the two boron atoms share a pair of electrons with bridging hydrogen atoms.
- There are two bridging hydrogen atoms, each forming a 3-centre-2-electron bond with the two boron atoms.
- Thus, there are 2 3-centre-2-electron bonds in B₂H₆.

5. **Final Count**:
- The total number of 2-centre-2-electron bonds is 4.
- The total number of 3-centre-2-electron bonds is 2.

### Answer:
The number of 2-centre-2-electron and 3-centre-2-electron bonds in B₂H₆ are **4 and 2**, respectively.

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