Charges of Common Elements and Polyatomic Ions

Group 1 elements (Li, Na, K)

1

Group 2 elements (Be, Mg, Ca)

2

Group 13 elements (Al)

3

Group 14 elements (C, Si)

±4 (usually covalent)

Group 15 elements (N, P)

-3

Group 16 elements (O, S, Se)

-2

Group 17 elements (F, Cl, Br, I)

-1

Group 18 elements (noble gases)

0 (no charge)

Fe (iron) can form

+2 or +3

Cu (copper) can form

+1 or +2

Sn (tin) can form

+2 or +4

Pb (lead) can form

+2 or +4

Zn (zinc)

2

Ag (silver)

1

Al (aluminum)

3

NH₄⁺

Ammonium

OH⁻

Hydroxide

N₃⁻

Azide

CN⁻

Cyanide

MnO₄⁻

Permanganate

BrO⁻

Hypobromite

C₂H₃O₂⁻

Acetate

BrO₃⁻

Bromate

IO₃⁻

Iodate

HCO₃⁻

Bicarbonate (or Hydrogen Carbonate)

HSO₄⁻

Bisulfate (or Hydrogen Sulfate)

HSO₃⁻

Bisulfite (or Hydrogen Sulfite)

H₂PO₄⁻

Dihydrogen Phosphate

ClO₂⁻

Chlorite

ClO⁻

Hypochlorite

NO₃⁻

Nitrate

NO₂⁻

Nitrite

SCN⁻

Thiocyanate

O₂²⁻

Peroxide

C₂O₄²⁻

Oxalate

CO₃²⁻

Carbonate

CrO₄²⁻

Chromate

Cr₂O₇²⁻

Dichromate

SO₄²⁻

Sulfate

SO₃²⁻

Sulfite

PO₄³⁻

Phosphate

PO₃³⁻

Phosphite

ClO₄⁻

Perchlorate

ClO₃⁻

Chlorate