When a photon is absorbed by an electron the electron moves from ground state to a higher energy lets say n=3. this electron can then drop back down and emit a photon of the exact energy as the photon that was absorbed. My question is why is there no work function or energy transfer as it where, when the electron moves up from ground to n=3? what made me think about this was the photo electric effect. the Kmax of an electron is hf-∅. I think i may be trying to think about it using classical physics instead of quantum.