What is the oxidation number of the sulfur atom in #Li_2SO_4#?
Sulfur in sulfate expresses it maximum oxidation state, its Group Number,
How? Well, as you know the sum of the oxidation numbers MUST equal the charge on the ion..........
Now oxygen generally assumes an oxidation number of
The charge of
Oxygen "in this case (because it is not a peroxide)" has a charge of
Sulfur must have a charge that will make(
Therefore the charge of sulfur