Cаtiоns: NH4+ = аmmоnium iоn Hg22+ = mercury(I) ion Anions: NO2- = nitrite ion NO3- = nitrаte ion SO32- = sulfite ion SO42- = sulfate ion PO43- = phosphate ion MnO4- = permanganate ion CO32- = carbonate ion HCO3- = hydrogen carbonate ion Cr2O72- = dichromate ion CrO42- = chromate ion CN- = cyanide ion OH- = hydroxide ion C2H3O2- = acetate ion ClO4- = perchlorate