Question

An electron in the n = 5 level of an H atom emits a photon of wavelength 4052.28 nm. To what energy level does the electron move?

Answer 1

From Rydburg's Equation ,
   Where R = Rydburg's constant = 10.96 x10⁶ m^-1
               λ = wavelength = 4052.28 nm = 4052.28x10^-9 m
               n_i = ?
               n_f = 5
Plug the values we get

                                   

                                    n²_i = 16

                                      n_i = 4

So the electron moves to 4th energy level