The oxidation number is also called oxidation state is the total number of electrons that an atom either gains or loses to form a chemical bond with another atom.
- Manganese(III) oxide is a chemical compound with the formula Mn2O3.
- Manganese oxide minerals have been used for thousands of years—by the ancients for pigments and to clarify glass
Since the oxidation state of oxygen is -2
Then assuming x is the oxidation state of Mn
2x + 3 (-2) = 0
2x = 6
or x = +3