Draw all the resonance forms of the sigma complex for nitration of bromobenzene at the ortho, meta, and para positions. Point out why the intermediate for meta substitution is less stable than the other two.
Nitration of bromobenzene -
In case of ortho and para attack of nitronium ion on bromobenzene there one more stable resonance structure; bromonium ion. Hence; meta substitution is less stable than the other two (ortho and para)