Mystery #4Tier 2-3emission / electrons
Why are fireworks different colours?
A firework that bursts deep red, the one beside it a brilliant green, another a cold electric blue. The bang is just hot gas, so where do the colours come from? Here is the strange part: the colour is not paint and it is not the flame. It comes from which metal was packed inside. Each metal gives off its own exact colour of light when it gets hot enough. Why would a metal glow a colour all of its own?
Your guess
Different metals give different colours: copper for blue-green, a sodium salt for yellow. What do you think the heat is doing inside those metal atoms to make them give off coloured light?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
Make a guess to unlock the hints and the answer.