* Fe2O3: This represents one molecule of iron(III) oxide. It contains:

* 2 iron (Fe) atoms

* 3 oxygen (O) atoms

* 3 Fe2O3: This means we have *three* of these molecules.

Calculation:

* Iron (Fe): 2 atoms/molecule * 3 molecules = 6 iron atoms

* Oxygen (O): 3 atoms/molecule * 3 molecules = 9 oxygen atoms

Total: 3 Fe2O3 contains 6 iron atoms and 9 oxygen atoms, for a total of 15 atoms.