SO2 Lewis Structure

[Shannon Moore 2L]

I understand that having one oxygen with a single bond and one oxygen with a double bond results in the lowest formal charge, but why can't the sulfur atom just have an expanded octet so that it has one lone pair and has double bonds with both oxygens? Wouldn't that result in each atom having 0 formal charge?

[Mohamed Mido]

I think you would use an expanded octet as a last resort. Although Oxygen prefers to have a neutral charge and two bonds, it doesn't mind having a -1 charge and if it were to share its electrons with sulfur then it would take sulfur a lot of energy to put its own electrons in a higher level orbital/shell, which is not as stable as just letting itself have a +1 charge and letting Oxygen have a -1 charge. Idk if I'm right though but it does make a little sense to me lol

[reva_bajjuri]

^^that is correct. you usually would expand the octet if there is a higher charge on an atom/an unlikely charge. for example, fluorine having a +1 charge would be an example of an unlikely charge on an atom.

[605291562]

I agree with what was said above I think expanded octets are the last resort and it is more stable for oxygen to have a charge than sulfur