1. Given that the ground energy level of a hydrogen atom is -13.6eV, the 1st excited state -3.4eV. The difference is 10.2eV. Imagine a photon of energy 11.0eV hits the electron at ground state. What will be the final result? Electron doesn't gets excited, photo bounces off with 11.0eV? or Electron goes to 1st excited state, and photon gets red-shifted by 10.2eV. 3. Somehow I think is the latter. There is partial energy loss by the photon, and red-shift happens. Am I right?