Posted: May 10, 2013 3:39 pm
by Evolving
Not sure what you mean by "transform", Matt.

if an atom or a molecule absorbs a photon, it enters into an excited state, and will usually fall back into a more relaxed state very shortly afterwards, emitting one or more different photons, each with a characteristic wavelength (thus helping us to detect what element this was, if we happen to be watching).