Common Polyatomic Ions
carbonate CO3 2-
bicarbonate HCO3 1-
phosphate PO4 3-
hydroxide OH 1-
peroxide O2 2-
cyanide CN 1-
sulfate SO4 2-
sulfite SO3 2-
nitrate NO3 1-
nitrite NO2 1-
ammonium NH4 +
acetate CH3COO 1-