• Question: Why does copper sulphate burn green?

    Asked by to Ian on 19 Jun 2014. This question was also asked by .
    • Photo: Ian Stephenson

      Ian Stephenson answered on 19 Jun 2014:

      Light is made up of photons, and each photon has a frequency. Each frequency (and/or mix of frequencies if there are many photons) appear to our eyes as a different colour.

      The frequency of a photon depends on how much energy it has.

      Atoms can emit photons when an electron receives some energy and then gets rid of that energy. If you’ve looked at electron’s in chemistry you’ll know they’re arranged in energy levels, so an electron with too much energy will jump to a higher orbit, then drop back down.

      The gaps between the levels that elections orbit is very specific to the type of atom, and in the case of copper it emits photons that have the right amount of energy to appear green to our eyes,

Comments