Question

What two things can happen to a substance when energy is added

Answer 1

quite a few things can happen to a substance. It can get HOTTER - its temperature rises. It can EXPAND, change its length,breadth, height (railway lines in UK often buckle by expansion in hot weather - when the UK manages to GET hot, that is). I think that its electrical resistance can change, and probably its density; the mass of, say, 1 cubic metre may change because the thing's got bigger, but the mass hasn't got bigger.
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