Question

Why heat has to be provided constantly when aluminium reacts with water? 

Answer 1

When aluminium reacts with water, providing heat will result into bond formation between aluminium (Al) and oxygen (O) to form aluminium oxide (Al2O3) with the release of hydrogen gas (H2)

Chemical reaction is as follows:-

     2Al + 3H2O + Heat = Al2O3 + 3H2

        Here '=' means "gives"

Answer 2

When aluminium reacts with water, providing heat will result into bond formation between aluminium and oxygen