Class 12 NEET Chemistry P Block Elements Questions

X - X bond     F - F   Cl - Cl  Br-Br  I-I
Bond dissociation  38    57  45.5  35.6
energy(kcl/mol)
The lower value of bond dissociation energy of fluorine is due to the high inter-electronic repulsions between non-bonding electrons in the 2p-orbitals of fluorine. As a result F - F bond is weaker in comparison to Cl Cl and Br - Br bonds.