Question: what are the chemical symbols for the two elements found iron oxide?
Answer: Three oxygen compounds of iron are known: ferrous oxide, FeO; ferric oxide, Fe2O3; and ferrosoferric oxide, or ferroferric oxide, Fe3O4, which contains iron in both +2 and +3 oxidation states. Ferrous oxide is a greenish to black powder used primarily as a pigment for glasses.