so i often hear the analogy of an atom being on the same scale as a foot ball in the center of a pitch, with the electrons all in their orbitals at some large distance away. in chemistry we have been discussing the difference in energy levels of electrons and using these to describe the colours of certain compounds. i am imagining that the spaces between atoms are much larger than the 'gap' a photon can fit through, so what is it that causes the photon to change electrons energy states? also, if the transparency of glass is explained by saying it has an amorphous structure, why does this make it transparent? i would have thought density played a part here, but what do i know? anyway, if you can clear any of this up for me, i'd be very grateful. thanks.