So in my physical chemistry class we have been looking into radiation, selection rules, etc.
Taking into account the discrete levels of energy an electron can have, I cannot understand why fluorescence and absorption spectra of compounds have continuous lines instead of discrete values.
If electrons in a system can only have a select number of energies, why is it that these graphs show a continuum of absorption and emission?
I also have this problem with blackbody radiation, since it is a continuous line for any temperature.