I want to so a spectra activity where students look at various light
sources and gas tubes with a diffraction grating. I also have a black
light and a fluorescent light. The black light shows five distinct lines,
and matches up with mercury on my spectrum chart. The spectrum for my
fluorescent light is similar to that of the black light, but with an extra
(blue) line. Has anyone else seen this? Do CFL's also contain mercury? I
am wondering if both lights contain mercury, why are the spectral lines
slightly different?