Learn what oxidation state is, how to calculate it, and how it relates to redox reactions. Find out the general rules, solved examples, and trends in oxidation states of different elements and compounds. How to find oxidation number & oxidation state - important concepts in chemistry. We go over the rules and make them very easy to understand. The oxidation state of each atom in a compound is the charge an atom would have if all its bonding electrons were transferred to the atom with the greater attraction for electrons. Atoms in their elemental form, such as O 2 or H 2, are assigned an oxidation state of zero. For example, the reaction of aluminum with oxygen to produce aluminum ... Oxidation State Definition Oxidation number of an atom is the charge that atom would have if the compound is composed of ions. It represents the number of electrons an atom gains or losses when bonded with other atom in a molecule.