0
oxidation number of an atom in the elemental state
equal to the charge of the ion
oxidation number of a monatomic ion
0
algebraic sum of the oxidation numbers in a formula
1+
usual oxidation number of hydrogen in a compound
1-
oxidation number of hydrogen in a hydride with an active metal
2-
usual oxidation number of oxygen in a compound
1-
oxidation number of oxygen in peroxides
2+
oxidation number of oxygen with fluorine
equal to the charge of the ion
algebraic sum of the oxidation numbers in a formula of a polyatomic ion