Question

Assign appropriate reason for the following:

The bond energy of F₂ is less than that of Cl₂.

Answer 1

1. Fluorine atoms are very small in size.
2. There are three lone pairs of electrons on each fluorine atom.
3. These lone pairs repel each other strongly.
4. The repulsion weakens the \[\ce{F - F}\] bond.
5. Hence, the bond dissociation energy of F₂ is lower than that of Cl₂.

This explains why F₂ has a weaker bond compared to Cl₂.