Video Transcript
Rusting is a term specific to iron. Which process does it describe?
Rusting is a process by which a reddish-brown substance known as rust is formed on the surface of certain metals. Only iron and certain iron alloys will form rust under specific conditions. This is because chemically rust or hydrated iron(III) oxide forms when iron combines with oxygen and water.
Rust is weak, brittle, and flaky. It will chip away over time, exposing more of the surface to oxygen and water, which will allow more rust to form. The rust will accumulate over time, reducing the iron object’s strength and stability. Rusting can be delayed and in some cases completely stopped, but once the harm has already been done, it is irreparable. Rusting is a form of corrosion, the gradual destruction or damage caused by a slow, irreversible, and spontaneous redox reaction between the surface of a substance and the environment.
It’s worth noting here that all rusting reactions are corrosion, but not all types of corrosion are rusting. Other metals can corrode, but only iron can corrode to form hydrated iron(III) oxide, the compound we call rust. Returning to the question, rusting is a term specific to iron that describes the process of corrosion.
