2 resonance structure.
O=S⁺-O⁻ and O⁻-S⁺=O, angles between S and O are 120°, bond order is 1,5.
As per the rule, oxidation number of alkaline earth metals in their compounds is +2. Oxidation number of oxygen in it's compounds is -2(except peroxides) and the sum of oxidation numbers of all the elements of a neutral compound is zero.
Mutual
They are balanced steadily which means they’re at the same point
