Answer
Both Na^+ and SO4^2- are present in Sodium Sulfate (Na2SO4).
Work Step by Step
To break down Na2SO4, you will look at the subscripts presents in the compound. Notice that $SO4^{2-}$ is a polyatomic ion, so it keeps the charge of 2-, and Sodium (Na) is in group I on the periodic table. So it will keep a charge of 1+.
