Question

Why does fluorine have low bond dissociation energy than cl?

Answer 1

There is your answer,

The size of fluorine is smaller than Chlorine and bromine. Due to which there is higher electron density on Fluorine. ... Due to this repulsion between the electrons both the atoms want to move apart. Hence the bond can be cleaved easily and the bond dissociation energy is less.

I hope it will help you lot.

Answer 2

Answer:

Flourine is smaller as compared to Chlorine. So, there is a large electron - electron repulsion in flourine which is less in case chlorine as in chlorine the last electron enters into 3rd shell. So, Bond enthalpy of flourine is more than chlorine