Question

Why is benzene aromatic?

Answer 1

Because it has `6` `pi` electrons constrained, and delocalized around a ring.

Explanation:

Benzene satisfies the Huckel criterion, i.e. ; it has `4n+2=6` `pi` electrons delocalized around a planar ring. This confers special stability, and special reactivity. While benzene is an aromatic carbocycle, heterocyclic aromatics exist, e.g. pyrrole, `C_4H_4NH`, furan, `C_4H_4O`, etc, in which the lone pairs on the heteroatom are delocalized.