Bond dissociation energy among halogens Among the halogens, why is it that the fluorine has the lowest bond dissociation enthalpy, considering the fact that fluorine is the smallest and the internuclear distance between the fluorine molecule is least and $2p-2p$ overlap should also very very strong ,the bond dissociation enthalpy should have been very high but it is lowest among the halogens. Why is it so??
The strength of the bond is due to 2 things : Difference in electronegativity and atomic radius of the elements .Halogens except fluorine , have a very big atomic radius so less bond energy.And they have 0 difference in electronegativity so even less bond energy.They both "want" to get the bonding pair of electrons closer to them , so because they cant both atoms are "unhappy".