In the following balanced chemical equation, what does the subscript number after oxygen in iron(III) oxide mean?
2 F e 2 O 3 + 3 C → 4 F e + 3 C O 2
Select one:

3 atoms of oxygen in iron (III) oxide

3 molecules of iron (III) oxide

3 molecules of oxygen in iron (III) oxide

3 atoms of iron (III) oxide