Why does the mixture of powdered iron oxide and powdered aluminum make thermite?

I was just wondering why it creates such intense heat, i mean what do those two substances have to do with fire.Why does the mixture of powdered iron oxide and powdered aluminum make thermite?
the reaction





Fe2O3 + 2 Al ---%26gt; 2 Fe + Al2O3 + heat


.....................................( LOTS of heat !!! )





This is a replacement reaction, not a combustion.


It produces very pure, molten iron.


It has been used to weld the broken drive shafts of steamships in an emergency.Why does the mixture of powdered iron oxide and powdered aluminum make thermite?
To my best knowledge it's not just the straight aluminum that does it. There has to be some water present too, as well as a bit of aluminum hydroxide.





That combination makes the aluminum *highly* prone to pulling oxygen, in a galvanic manner, from metals it is exposed to. And iron holds on to oxygen fairly intensely as well, so when the iron oxide loses its oxygen, it heats up and *melts*.





I think it has something to do with the way the oxygen binds, whether it's single-bound (with one electrical charge) or double-bound (with two, clearly).





I hope this helps. Edit: The Answerer above me is correct. It's a case of triple-bound chemistry, basically. Lots of energy in those molecules there.