Question

How will you show that Al is more reactive than Fe?

Answer 1

Aluminium is more reactive than iron yet there is less corrosion of aluminium when both are exposed to air.Aluminium developes a protective(something that protects)layer of aluminium by slowly reacting(to act upon each other)with oxygen present in air.
After the formation of this layer,air cannot react with aluminium present.Hence there is only less erosion by chemical action
In compare,iron cannot form protective layer,hence it is easily get damaged by corrosion