Carbanion contains _______ electrons in valence shell

Options

A. 8
B. 6
C. 4
D. 2

Answer

To determine how many electrons are present in the valence shell of a carbanion, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Carbanion**: A carbanion is a negatively charged ion where carbon has an extra electron. This extra electron contributes to the total count of valence electrons.

2. **Valence Electrons of Carbon**: Carbon, in its neutral state, has 4 valence electrons. This is because it is in group 14 of the periodic table.

3. **Extra Electron in Carbanion**: Since a carbanion has an extra electron due to its negative charge, we need to add this to the 4 valence electrons.

4. **Calculating Total Valence Electrons**:
- Neutral Carbon: 4 valence electrons
- Extra electron (due to negative charge): +1 electron
- Total = 4 + 1 = 5 valence electrons.

5. **Considering Bonding**: In a carbanion, carbon typically forms three bonds with other atoms (like hydrogen or alkyl groups) and retains one lone pair of electrons. This means the carbon atom is involved in bonding with three substituents.

6. **Final Count of Electrons**:
- 4 electrons from the carbon atom itself (as part of the bonds)
- 1 extra electron due to the negative charge
- Total = 4 (from bonds) + 1 (extra) = 5 electrons.

7. **Conclusion**: Therefore, a carbanion contains **5 electrons** in its valence shell.

### Final Answer:
Carbanion contains **5 electrons** in its valence shell.