In diborane, the number of electrons that account for bonding in the bridges is

Options

A. six
B. two
C. eight
D. four

Explanation

To determine the number of electrons that account for bonding in the bridges of diborane (B2H6), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of Diborane**:
- Diborane has the chemical formula B2H6. It consists of two boron (B) atoms and six hydrogen (H) atoms. The structure features two boron atoms connected by hydrogen atoms.

2. **Understand the Bonding in Diborane**:
- In diborane, there are two types of bonds: terminal B-H bonds and bridge B-H-B bonds. The terminal B-H bonds are regular two-center, two-electron bonds, while the bridge bonds are unique.

3. **Focus on the Bridge Bonds**:
- The bridge bonds in diborane are B-H-B bonds. Each bridge bond involves three atoms: two boron atoms and one hydrogen atom. This type of bond is known as a three-center, two-electron bond.

4. **Count Electrons in Bridge Bonds**:
- Each bridge bond (B-H-B) contains a total of 2 electrons, which are shared among the three atoms involved (2 boron and 1 hydrogen).
- Since there are two bridge bonds in diborane, we can calculate the total number of electrons involved in the bridge bonding.

5. **Calculate Total Electrons in Bridges**:
- Total electrons in bridge bonds = Number of bridge bonds × Electrons per bridge bond
- Total electrons in bridge bonds = 2 bridge bonds × 2 electrons per bridge bond = 4 electrons.

### Final Answer:
The number of electrons that account for bonding in the bridges of diborane is **4 electrons**.

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