Eli5 How come some metals rust and others don’t?

Question

Eli5 How come some metals rust and others don’t?

In: Chemistry

Answer 1

Rust is specifically Iron oxide, therefore non-iron based metals won’t rust, but they will oxidize.

Iron happens to be a very common metal so we see rusted things quite often, but copper and brass will oxidize to give you the green layer on the Statue of Liberty. Aluminum quickly oxidizes and you only ever see oxidized aluminum but since its still fairly shiny you don’t notice.

Some iron based metals like stainless steel will have other metals mixed in such as chromium that stay shinier and reduce the formation of rust, but they can still oxidize and pick up a duller finish, its just not flaky rust