Question

Why does meta positions don't show mesomeric effect?

Answer 1

Therefore, electrophiles would attack the meta position. ... Why do the resonance effect and hyperconjugation only affect ortho and para, and ...

Answer 2

Answer:

Why (-NO2) group shows its effect only at ortho- and para-position and not at meta–position? Presence of nitro group at ortho- and para-positions withdraws the electron density from the benzene ring and thus facilitates the attack of the nucleophile on haloarene.