what causes rust on iron
The iron oxide particles remain suspended in the water, but when the water evaporates, the particles remain, forming a reddish coating on the surface of the iron. Without the presence of water, objects cannot rust. Other metals besides iron and steel can rust when exposed to moisture, but not all rust is ârust-colored.â For instance, when copper or bronze rusts, it turns green. The green crust is called a patina.