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.
the oxygen atoms in iron oxide have more mass than the iron atoms in pure iron.
iron oxide has oxygen atoms, and pure iron does not.
the iron atoms in iron oxide have more mass than pure iron.

Explanation:

Rusting is a chemical reaction where iron combines with oxygen in the air to form iron - oxide. Since iron oxide contains oxygen atoms in addition to iron atoms, its mass is greater than that of pure iron. The oxygen atoms contribute to the extra mass.

Answer:

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