Give suitable examples of negative ions and positive ions having aromatic nature.

(N/A) Aromatic ions must follow $H$ückel's rule,which states that a planar,cyclic,conjugated system with $(4n + 2) \pi$ electrons is aromatic.
$1$. Negative ion: Cyclopentadienyl anion $(C_5H_5^-)$. It has $6 \pi$ electrons $(n=1)$,making it aromatic.
$2$. Positive ion: Cycloheptatrienyl cation $(C_7H_7^+)$,also known as the tropylium ion. It has $6 \pi$ electrons $(n=1)$,making it aromatic.