Polyatomic Ions

NH 4 + ammonium

OH - hydroxide

NO 3 - nitrate

CO 3 2- carbonate

SO 4 2- sulfate

PO 4 3- phosphate

HCO 3 - hydrogencarbonate

HPO 4 2- hydrogenphosphate

H 2 PO 4 - dihydrogenphosphate