Why is Aluminium special in the reactivity series?
Aluminum is so reactive that it does not naturally occur as pure metal. That and the high reduction potential (-1.66 volts) would seem to indicate that it would not be a useful material. But when aluminum oxidizes, it forms a thin surface layer of aluminum oxide that is tightly bound to the surface. This gives it a very high resistance to further corrosion, and combined with its abundance and ease of recycling, amke it one of the most useful of metals.
