Oxidation Numbers

Positive Oxidation Numbers

H⁺ - Hydrogen
Na⁺ - Sodium
K⁺ - Potassium
Ag⁺ - Silver
Cu⁺ - Copper
AH₄⁺ - Ammonium

Pb²⁺ - Lead
Zn²⁺ - Zinc
Ca²⁺ - Calcium
Ba²⁺ - Barium
Mg²⁺ - Magnesium
Cu²⁺ - Copper
Hg²⁺ - Mercury II
Hg₂²⁺ - Mercury I
Fe²⁺ - Iron (Ferrous)
Sn²⁺ - Tin
Cr²⁺ - Chromium

Al³⁺ - Aluminum
Fe³⁺ - Iron (Ferric)
Cr³⁺ - Chromium

Sn⁴⁺ - Tin

Negative Oxidation Numbers

F^- - Flouride
Cl^- - Chlorine
Br^- - Bromine
I^- - Iodide
NO₂^- - Nitrite
NO₃^- - Nitrate
OH^- - Hydroxide
ClO^- - Hypochlorite
ClO₂^- - Chlorite
ClO₃^- - Chlorate
ClO₄^- - Perchlorate
MnO₄^- - Permanganate

O^2- - Oxide
S^2- - Sulfide
SO₃^2- - Sulfite
SO₄^2- - Sulfate
CO₃^2- - Carbonate
CrO₄^2- - Chromate
Cr₂O₇^2- - Dichromate
O₂^2- - Peroxide

PO₄^3- - Phosphate

These are the number of electrons necessary to restore an atom in a combined state to its elemental form.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.