Thermite

[carsonking]

If you say put 5kg of it on top of a block of flats, how many floors would it go through before going out?

[theprof]

No one can answer this question for you. It depends on too many factors. For example, are the floors made of concrete or steel? Are the floors made of concrete and steel?How thick are the floors?

In addition, chemically there is no such thing as thermite. Thermite is a generic term for a mix of a metal oxide (the oxidiser) with a metal powder (the fuel). Whilst the commonest type is a mix of aluminium powder and ferric oxide, there are other thermites to be had. Fuels can be titanium, zinc and magnesium whilst the oxidisers include chromium, boron, manganese and iron salts.

What all this means is that the temperature of a burning thermite mix can vary tremendously. As a result, it's melting ability varies. Whilst one thermite mix might melt concrete quickly another could take hours or possibly have no effect at all..

http://books.google.co.uk/books?id=Qp55OCtxugE C&pg=PA200&lpg=PA200&dq=thermite+concrete&sour ce=bl&ots=ARxEcwprIY&sig=U_1Wn_4i5HOgxl2p45Q26 oXia1E&hl=en&ei=JrMaSqf5AYTMjAek4b3yDA&sa=X&oi =book_result&ct=result&resnum=1

Even if the thermite got through the top floor, it would disperse over a wider area during free fall causing it to become not only less effective but unpredictable in action.

If you have the time to spare, have a look at the conspiracy theories behind the 9/11 explosions at the WTC and the thermate/thermite theories.

http://www.rense.com/general75/thrm.htm

There's loads of other links on the web discussing these theories