Comment on the nature of two $S-O$ bonds formed in $SO_{2}$ molecule. Are the two $S-O$ bonds in this molecule equal?

(N/A) The electronic configuration of $S$ is $1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{4}$.
During the formation of $SO_{2}$, one electron from the $3p$ orbital is promoted to the $3d$ orbital, and $S$ undergoes $sp^{2}$ hybridization. Two of these hybrid orbitals form sigma bonds with two oxygen atoms, and the third contains a lone pair.
The remaining $p$-orbital and $d$-orbital on $S$ contain an unpaired electron each. One of these electrons forms a $p\pi-p\pi$ bond with one oxygen atom, and the other forms a $p\pi-d\pi$ bond with the other oxygen atom.
Due to resonance, $SO_{2}$ exists as a resonance hybrid of structures $I$ and $II$. As a result, both $S-O$ bonds are equivalent in length $(143 \ pm)$ and possess a partial double bond character.