polyatomic ions

ammonium, +1

hydronium, +1

mercury (I), +1

dihydrogen phosphite, -1

dihydrogen phosphate, -1

hydrogen carbonate, -1

hydrogen sulfate, -1

hydrogen sulfite, -1

nitrite, -1

nitrate, -1

hydroxide, -1

acetate, -1

chromite, -1

cyanide, -1

cyanate, -1

thiocyanate, -1

permanganate, -1

hypochlorite, -1

chlorite, -1

chlorate, -1

perchlorate, -1

hypobromite, -1

bromite, -1

bromate, -1

perbromate, -1

hypoiodite, -1

iodite, -1

iodate, -1

periodate, -1

azide, -1

hydrogen phosphite, -2

hydrogen phosphate, -2

carbonate, -2

sulfite, -2

sulfate, -2

thiosulfate, -2

oxalate, -2

chromate, -2

dichromate, -2

peroxide, -2

disulfide, -2

oxide, -2

sulfide, -2

phosphate, -3

arsenite, -3

arsenate, -3

nitride, -3

silicate, -2

Superoxide -

molybdate, -2