The state of hybridisation of central atom in dimer of `BH_(3)` and `BeH_(2)` IS `:`

Options

A. `sp^(2), sp^(2)`
B. `sp^(3), sp^(2)`
C. `sp^(3), sp^(3)`
D. `sp^(2), sp^(3)`

Explanation

To determine the state of hybridization of the central atom in the dimers of BH₃ and BeH₂, we will follow these steps:

### Step 1: Identify the Dimer Formed
- **BH₃** dimerizes to form **B₂H₆** (Diborane).
- **BeH₂** dimerizes to form **Be₂H₄**.

### Step 2: Analyze the Structure of B₂H₆
- In B₂H₆, the boron atoms are connected by bridging hydrogen atoms.
- The structure consists of two boron atoms and six hydrogen atoms, where two hydrogen atoms act as bridges between the two boron atoms.

### Step 3: Count the Sigma Bonds in B₂H₆
- In B₂H₆, there are four B-H sigma bonds (two terminal and two bridging).
- The total number of sigma bonds is 4.

### Step 4: Determine Hybridization of Boron in B₂H₆
- The hybridization can be determined using the formula:
\[ \text{Hybridization} = \text{Number of sigma bonds} + \text{Lone pairs} \]
- Since boron has no lone pairs and forms 4 sigma bonds, the hybridization is:
\[ \text{Hybridization} = 4 \rightarrow sp³ \]

### Step 5: Analyze the Structure of Be₂H₄
- In Be₂H₄, beryllium atoms are also connected by hydrogen atoms.
- The structure consists of two beryllium atoms and four hydrogen atoms.

### Step 6: Count the Sigma Bonds in Be₂H₄
- In Be₂H₄, there are four Be-H sigma bonds.
- The total number of sigma bonds is also 4.

### Step 7: Determine Hybridization of Beryllium in Be₂H₄
- Using the same formula:
\[ \text{Hybridization} = \text{Number of sigma bonds} + \text{Lone pairs} \]
- Since beryllium also has no lone pairs and forms 4 sigma bonds, the hybridization is:
\[ \text{Hybridization} = 4 \rightarrow sp³ \]

### Conclusion
- The hybridization of the central atom in the dimer of BH₃ (B₂H₆) is **sp³**.
- The hybridization of the central atom in the dimer of BeH₂ (Be₂H₄) is also **sp³**.

### Final Answer
The state of hybridization of the central atom in the dimer of BH₃ and BeH₂ is **sp³**.

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