Question

Question #01a9d

Answer 1

You can find the wavelength of the photon the electron emits when it returns.

Explanation:

Once you have the wavelength, use the equation

`E = (hc)/lamda`

to find the energy, where `h` is Planck's constant `(6.626 xx 10^(-34)` `"J s")`, `c` is the speed of light `("300,000,000 m/s")`, and `lamda` (upside down y) is the wavelength.