# An He1+ ion absorbs a photon with a frequency of 2.53 x 1018 Hz. If the energy of the final state is 4.35 x 10-15 J, calculate the energy of the initial state.

Question

An He1+ ion absorbs a photon with a frequency of 2.53 x 1018 Hz. If the energy of the final state is 4.35 x 10-15 J, calculate the energy of the initial state.