polyatomics

ammonium NH4+ mercury (I) Hg2+2 nitrate NO3- nitrite NO2- chlorate ClO3- bromate BrO3- iodate IO3- permanganate MnO4- hydroxide OH- cyanide CN- thiocynate SCN- acetate C2H3O2- hydrogen carbonate (bicarbonate) HCO3- phosphate PO4-3 carbonate CO3-2 sulfate SO4-2 sulfite SO3-2 thiosulfate S2O3-2 chromate CrO4-2 dichromate Cr2O7-2 oxalate C2O4-2