$\mathrm{SO}_{2}=6+6(2)=18 \mathrm{e}-16 \mathrm{e}=2 \mathrm{e} \rightarrow 1$ lone pair

$\rightarrow \mathrm{G} . \mathrm{S}=[\mathrm{Ne}] 3 \mathrm{s}^{2} 3 \mathrm{p}^{4}$

2 Unpaired electron $1^{\text {st }}$ E.S. $=[\mathrm{Ne}] 3 \mathrm{s}^{2} 3 \mathrm{p}^{3} 3 \mathrm{d}^{1}$

4 unpaired electron $\mathrm{O} \rightarrow 1 \mathrm{s}^{2} 2 \mathrm{s}^{2} 2 \mathrm{p}^{4}$

$\rightarrow$ Geometry of $\mathrm{SO}_{2}$ is BENT/ANGULAR

$\rightarrow$ one $\mathrm{p} \pi-\mathrm{p} \pi$ and one $\mathrm{p} \pi-\mathrm{d} \pi$ Bond

$\rightarrow 2 \pi$ Bonds

$\rightarrow 1$ lone pair on the central atom.