Rachel is a 35 year old school teacher who has no man in her life and lives with her mother.
Each element give off a particular color when heated in a flame. (Some are colorless). Copper gives off a green flame but to do that there must be some copper compound IN the flame. (there are many other elements that also could be causing a green flame).
Those colors are as distinctive to each element as fingerprints are to people. As an easy experiment to try at home, put a little table salt in a flame. You will see the same yellow glow as that of a sodium street light, in which the sodium electrons are kicked about by an electric current instead of a flame. Also, a bit of boric acid, which you can get at a pharmacy, will produce a lovely green flame due to the element boron.