Use the chemical reaction to answer the question.

4Fe + 3O↓(2) -> 2Fe↓(2) O↓(3)

What happens to atoms of Fe and O↓(2) during the reation?
They gain mass.
They maintain their properties.
They are lost.
They are rearranged.

They are rearranged. During the reaction, the atoms of Fe and O(2) are rearranged to form iron oxide (Fe2O3).