Know the charges of Group 1, 2, 3, 5, 6 and 7 ions and Ag⁺, Cu²⁺, Fe²⁺, Fe³⁺, Pb²⁺, Zn²⁺, H⁺, OH⁻, NH₄⁺, CO₃²⁻, NO₃⁻ and SO₄²⁻.