atomic spectroscopy vs. molecular spectroscopy

[Lucy Wang 2J]

can someone explain the point on the Unit 2: Outline that says"with respect to electron transitions that give rise to a UV or visible spectrum: understand the difference between electronic transitions in atomic orbitals and electronic transitions in molecular orbitals"

or if u could point me to where it is explained in the lectures/textbook that'd be super helpful

[David Chibukhchian 2G]

I had this same question regarding that part of the outline. However, I think for that topic we just have to understand that molecular spectroscopy is a bit more complicated as a result of multiple electrons, especially compared to the atomic spectroscopy for hydrogen. In multi-electron atoms and molecules, the shells are not degenerate, meaning they have subshells with different energies. As a result, molecular spectroscopy is going to be more complex and take that increased number of electrons (and their interactions in the molecule) into account. I'm also a bit confused, but I think that's what we have to know in general. I hope that helps!

[Abby Lam 3F]

I'm not sure, but I think molecular spectroscopy is more complex because molecules are more complex structures. Instead of only studying the behavior of one electron, we can study the behavior of a molecule. It would be great if someone could further clarify!