What is happening in Thermite that allows Aluminum and Iron Oxide to burn so hot? Also, how is aluminum and iron able to burn like that considering they are metals?
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To answer the second part of your question:
> Also, how is aluminum and iron able to burn like that considering they are metals?
Most metals will burn VERY well if exposed to oxygen and heat. Burning is just rapid oxidation, after all, and oxygen is voracious and will not hesitate to bond with anything even remotely accepting. Metal fires are a major concern in some settings and are both incredibly hot and very difficult to extinguish – they are even their own “class” of fire (class D).
There are three things that keep metal from being on fire basically 100% of the time:
– a high heat requirement to ignite, as opposed to corrosion which happens at lower temperatures (but takes longer).
– the fact that for large chunks of metal, the outside has either already reacted with oxygen and blocks access for oxygen to get to the unoxidized metal inside.
– in some cases the metal has either entirely or partially been made into an alloy that is more resistant to oxidation – think stainless steel, which is iron mixed with gallium in order to strengthen metallic bonds and keep oxygen from joining the party and causing rust, or
If you want to burn a metal, simply give it lots of heat and free oxygen, and increase its surface area (typically done by grinding it to a powder). And that’s how thermite works. You heat aluminum powder and iron oxide enough with a starter, and the iron oxide will separate and the desperate oxygen will grab whatever it can bond with – and at the temperatures of thermite, aluminum is something it can bond with. This reaction generates heat (much like it takes heat to separate the iron from the oxygen), and that leads to a chain reaction where the aluminum oxide formation generates enough heat to free more iron and oxygen and cause more reactions with aluminum. Eventually you’ll run out of aluminum or iron oxide, but in the meantime you’ll generate enormous amounts of heat.
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