Bond energy is highest in the molecules

The increasing order of B.E in halogens is ${\mathrm{Cl}}_2>{\mathrm{Br}}_2>{\mathrm{F}}_2>{\mathrm{I}}_2$

(242.44 > 192.70 > 154.66 > 150.90 KJ${\mathrm{mol}}^{-}$)

In ${\mathrm{Cl}}_2$ molecule, atomic size of Cl is larger than the size of fluorine, F. Due to this reason the lone pair – lone pair’ repulsions is low in ${\mathrm{Cl}}_2$than in ${\mathrm{F}}_2$.Hence, the bond dissociation energy is highest for chlorine molecule than the remaining molecules.

Note: For bromine and iodine molecules the bond dissociation energy is low than chlorine. Because the size of Br and I is large than Cl.