Answer
1. Barium Sulphate: $Ba SO_{4}$: $Ba^{2+}$ (Barium), $SO_{4}^{2-}$ (Sulphate)
2. Magnesium Nitrate: $Mg(NO_{3})_{2}$: $Mg^{2+}$ (Magnesium), $NO_{3}^{-}$ (NItrate)
3. Sodium Acetate: $CH_{3}COONa$: $Na^{+}$ (Sodium), $CH_{3}COO^{-}$ (Acetate)
Work Step by Step
Write the name and electrical charge on each ion.
Transpose to get the formula.