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)
Responses

The oxygen atoms in iron oxide have more mass than the iron atoms in pure iron.
The oxygen atoms in iron oxide have more mass than the iron atoms in pure iron.

There are more iron atoms in iron oxide than in pure iron.
There are more iron atoms in iron oxide than in pure iron.

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

The iron atoms in iron oxide have more mass than pure iron.

Answer 1

Iron oxide has oxygen atoms, and pure iron does not. When iron rusts it combines with oxygen from the air, and the added oxygen increases the mass.