Question: 1. A ground states helium electron annihilates a 243 Å photon and then emits a photon of 2.46 1015 Hz. What is the electron's final state binding energy in eV?
2. A ground state hydrogen atom absorbs 10.20345 eV of excitation energy. Afterward, the electron absorbs a 4860.512 Å photon. What is the binding energy of the electron's final state?