why dissociation energy of f2(bond length 143pm) is less than cl2(bond length 199pm) and br2( bond length 228 pm), even when it's bond length is less? please answer fast (the reason of interelectronic repulsion don't convince me because if there is an inter electronic repulsion than why it's bond length is less)
Fluorine (F2), Chlorine (Cl2) and Bromine (Br2), all have three lone pair of electrons on each atom of Fluorine, chlorine and Bromine atoms. The size of fluorine is smaller than Chlorine and bromine. Due to which there is higher electron density on Fluorine. Due to smaller size and higher electron density there is repulsion between the electrons which is known as interelectronic repulsion. 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.