Question

when iron rusts and forms iron oxide, the iron oxide has more mass than the iron. which statement correctly explains this difference in mass? (1 point)
there are more iron atoms in iron oxide than in pure iron.
iron oxide has oxygen atoms, and pure iron does not.
the oxygen atoms in iron oxide have more mass than the iron atoms in pure iron.
the iron atoms in iron oxide have more mass than pure iron.

Explanation:

Rusting is a chemical reaction where iron combines with oxygen from the air to form iron oxide. Iron oxide has more mass than iron because it contains oxygen atoms in addition to iron atoms. Pure iron only has iron atoms.

Answer:

Iron oxide has oxygen atoms, and pure iron does not.