Oxidation

Oxidation Number:

A number assigned to an atom in a molecular compound or molecular ion that indicates the general distribution of electrons among the bonded atoms.

1. The oxidation number of any uncombined element is O.

2. The oxidation number of a monatomic ion equals the charge on the ion.

3. The more electronegative element in a binary compound is assigned the number equal to the charge it would have if it were an ion.

4. The oxidation number of fluorine in a compound is always -1.

5. Oxygen has an oxidation number -2 unless it is combined with F, when it is +2, or it is in a peroxide, when it is -1.

6. The oxidation state of  hydrogen in most of its compounds is +1 unless it is combined with a metal in which case it is -1.

7. In compounds, the elements of groups 1 and 2 as well as aluminum have oxidation number of  +1,+2, and +3, respectively

8. The sum of the oxidation numbers of all atoms in a neutral compound is O.

9. The sum of the oxidation number of all atoms in a polyatomic ion equals the charge of the ion.