polyatomic ions (most common)

(C2H3O2)^-

Acetate

(HSO4)^-

Hydrogen Sulfate

(HCO3)^-

Hydrogen carbonate

(NO2)^-

Nitrite

(NO3)^-

Nitrate

(OH)^-

Hydroxide

(SO3)^2-

Sulfite

(SO4)^2-

Sulfate

(CO3)^2-

Carbonate

(O2)^2-

Peroxide

(PO3)^3-

Phosphite

(PO4)^3-

Phosphate

(NH4)^+

Ammonium

(H3O)^+

Hydronium