Determine the number of $\sigma$ and $\pi$ bonds in the following molecules:
$(i)$ $O_2$
$(ii)$ $N_2$
$(iii)$ $C_6H_6$ (Benzene)
$(iv)$ $O_3$ (Ozone)

(N/A) The number of $\sigma$ and $\pi$ bonds are calculated as follows:
$(i)$ $O_2$ $(O=O)$: $1 \sigma, 1 \pi$.
$(ii)$ $N_2$ $(N\equiv N)$: $1 \sigma, 2 \pi$.
$(iii)$ $C_6H_6$ (Benzene): It has $12 \sigma$ bonds ($6$ $C-C$ and $6$ $C-H$) and $3 \pi$ bonds.
$(iv)$ $O_3$ (Ozone): The resonance structure shows $2 \sigma$ bonds and $1 \pi$ bond (delocalized over the structure).