basic chem polyatomic ions

hydronium

H₃O⁺

ammonium

NH₄⁺

acetate

CH₃CO₂^- or CH₃COO^-

cyanide

CN^-

hypochlorite

CIO^-

chlorite

CIO₂^-

chlorate

CIO₃^-

perchlorate

CIO₄^-

hypobromite

BrO^-

bromite

BrO₂^-

bromate

BrO₃^-

perbromate

BrO₄^-

hypoiodite

IO^-

iodite

IO₂^-

iodate

IO₃^-

periodate

IO₄^-

dihydrogen phosphate

H₂PO₄^-

hydrogen carbonate or bicarbonate

HCO₃^-

hydrogen sulfate or bisulfate

HSO₄^-

hydroxide

OH^-

permanganate

MnO₄^-

nitrate

NO₃^-

nitrite

NO₂^-

carbonate

CO₃^2-

chromate

CrO₄^2-

dichromate

Cr₂O₇^2-

peroxide

O₂^2-

hydrogen phosphate

HPO₄^2-

hydrogen phosphate

HPO₄^2-

sulfate

SO₄^2-

sulfite

SO₃^2-

thiosulfate

S₂O₃^2-

phosphate

PO₄^3-

phosphite

PO₃^3-