In an experiment with hydrogen atoms, an emission line arisen from the electron transitioin from a state with a principal quantum number n_i to state with a principal quantum number n_f is observed at 6.20*10¹⁴ Hz. a) Determine n_i and n_f.

b) Determine the initial linear momentum of the electron. c) If the dygrogen atoms are replaced with singly charged helium ions, i.e., ions comprising a single electron orbiting around its nucleus that contains two proton and two neutrons, what is the frequency of the emission line arising from the electron transition between the same two states?