What is the Lewis structure of #S_2O_8^(2-)#?
A reasonable Lewis structure for
Note that by definition, the oxidation state is the charge left on the central atom when all the bonding pairs of electrons ARE BROKEN, with the charge assigned to the most electronegative atom. But since the oxygen atoms have equal electronegativities, we CONCEIVE that the electrons are SHARED, and thus:
And thus the central peroxo linkage features oxygens in the same oxidation state as