Haloarenes are extremely less reactive to nucleophilic substitutions due to resonance stabilization of the molecule. The electron pairs on halogen atom are conjugated with ϖ-electrons of the aryl ring and the above resonating structures are possible. The C—X bond gains a partial double bond in resonance and thus it becomes difficult for cleavage of the bond, making is less reactive. There is also a difference in the hybridization of the carbon atom in the C—X bond. The carbon atom attached to halogen is sp² hybridised unlike halloalkanes which are sp³ hybridised. The sp² hybridised carbon holds the halogen more tightly, with a smaller bond length compared to the carbon atom attached to the halogen in sp³ hybridisation in haloalkane.