Amongst the C-X bond the correct bond energy order is

Options

A. `C-CI gtC-Br gt C-I`
B. `C-I gt C- CI gtC-Br`
C. `C-Br gt C-CI gt C-I`
D. `C-I gt C-Br gt C-CI`

Answer

To determine the correct bond energy order among the C-X bonds (where X represents halogens such as F, Cl, Br, and I), we need to analyze the bond energies based on the size of the halogen atoms and the effective overlap of their orbitals with carbon.

### Step-by-Step Solution:

1. **Understanding Bond Energy**:
- Bond energy is the amount of energy required to break a bond between two atoms. The stronger the bond, the higher the bond energy.

2. **Analyzing the Size of Halogens**:
- The halogens in the order of increasing atomic size are: Fluorine (F) < Chlorine (Cl) < Bromine (Br) < Iodine (I).
- As the size of the halogen increases, the distance between the nucleus of the carbon atom and the halogen atom also increases.

3. **Effective Overlap of Orbitals**:
- The strength of a bond is influenced by the effective overlap of the atomic orbitals of the two atoms involved in the bond.
- A better overlap results in a stronger bond and thus a higher bond energy.
- Carbon and Fluorine have a comparable size, allowing for good overlap.
- As we move down the group from F to I, the size of the halogen increases, leading to poorer overlap with carbon.

4. **Comparing C-F, C-Cl, C-Br, and C-I Bonds**:
- C-F bond: Strongest due to good overlap.
- C-Cl bond: Weaker than C-F but stronger than C-Br and C-I.
- C-Br bond: Weaker than C-Cl but stronger than C-I.
- C-I bond: Weakest due to the largest size and least effective overlap.

5. **Conclusion**:
- The order of bond energies for the C-X bonds is:
- C-F > C-Cl > C-Br > C-I

### Final Answer:
The correct bond energy order among the C-X bonds is: **C-F > C-Cl > C-Br > C-I**.