Why F-F bond is weaker than Cl-Cl bond?

Answer 1

bond energy (in kJ/mol)

F-F:158

Cl-Cl: 244

Hence, in order of decreasing bond strength:

Cl-Cl => => (F-F) =>

Fluorine is an anomaly.

Bond strength decreases from chlorine to iodine as down the group, the atomic size becomes larger and thus the valence electron orbitals become more diffused, causing the overlap of orbitals to become less effective. Therefore the halogen-halogen bond becomes weaker.

Fluorine is an exception due to its extremely small size. The F-F bond length is so short that the lone pairs of electrons on the fluorine atoms repel each other and weakens the F-F bond.

I hope that answers your question.

Answer 2

The F-F bond is weaker than the Cl-Cl bond because fluorine is a smaller atom with higher electronegativity, leading to stronger repulsion between the electron clouds and increased electron-electron repulsion. This weaker bond strength makes it easier to break the F-F bond compared to the Cl-Cl bond.

Answer 3

No, the N-F bond is stronger than an F-F bond