<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> Rust is an iron oxide, usually red oxide formed by the redox reaction of iron and oxygen in the presence of water or air moisture . Several forms of rust are distinguishable both visually and by spectroscopy, and form under different circumstances . Rust consists of hydrated iron (III) oxides Fe O nH O and iron (III) oxide - hydroxide (FeO (OH), Fe (OH)). </P> <P> Given sufficient time, oxygen, and water, any iron mass will eventually convert entirely to rust and disintegrate . Surface rust is flaky and friable, and it provides no protection to the underlying iron, unlike the formation of patina on copper surfaces . Rusting is the common term for corrosion of iron and its alloys, such as steel . Many other metals undergo similar corrosion, but the resulting oxides are not commonly called rust . </P>

The reaction of iron to form rust is called