I have this question from an exam paper:
"The excitation and relaxation processes involving electrons usually takes place at the same frequency or wavelength, although there are exceptions.
Using simple diagrams explain the above statement and show clearly how the most important exception occurs.
When this happens what is the result? Why is so much important attached to this type of spectroscopy? Comment upon the application of this spectroscopy in the analysis of drug metabolites in blood"
Is this question referring to Fluorescence spectroscopy as the exception?