Although aluminium is above hydrogen in the electrochemical series, it is stable in air and water Why?

Although aluminium is above hydrogen in the electrochemical series, it

1.	Although aluminium is above hydrogen in the electrochemical series, it is stable in air and water Why?
Answer» Solution :The THIN protective film of oxide, `Al_2O_3` is FORMED on the surface of aluminium. This PROTECTS the metal from further ATTACK of air and water. Thus the metal is stable in air and water.