Ammonium

Hint: the number of atoms within ()

NH(4)+

Hydronium

H(3)O+

Mercury(I)

Hg(2)2+

Info: It is correct, Hg is an exception.

Acetate

C(2)H(3)O(2)-

Azide

Hint: N(3)-

Carbonate

Co(3)2-

Chlorate

ClO(3)-

Chlorite

ClO(2)-

Chromate

CrO(4)2-

Cyanide

CN-

Dichromate

Cr(2)O(7)2-

Dihydrogen phosphate

H(2)PO(4)-

Hydrogen Carbonate

HCO(3)-

Info: aka bicarbonate

Hydrogen phosphate

HPO(4)2-

Hydrogen Sulfide AKA bislulfate

HSO(4)

Hydroxide

Hint: OH-

Hypochlorite

ClO-

Nitrate

NO(3)-

Oxalate

C(2)O(4)2-

Perchlorate

Hint: ClO(4)-

Permanganate

MnO(4)-

Peroxide

O(2)2-

Phosphate

PO(4)3-

Phosphite

PO(3)3-

Sulfate

Hint: SO(4)2-

Sulfite

Hint: SO(3)2-

Sulfite

Hint: SO(3)2-

thiocyanate

SCN-