Reading Assignment 18

Most difficult part of the material

I dont really understand the Franck-Condon principle, especially the final paragraph in 12.7 about dissociating of molecules if the excited electronic state is not bound.

Most interesting part of the material

How the abundance of isotopes can be accounted for by the spectra of the vibrational states. THe spectrum for different isotopes will differ in the vibrational frequencies. What was more interesting was that we can see the relative abundance of each of the isotopes by looking at the intensities of the spectral lines.