1. The problem statement, all variables and given/known data I'm trying to figure out what paths the electrons take when transitioning between stationary orbits. For example if there are 4 orbits: n1, n2, n3, n4; How do I know if the electron goes from n4 ---> n1 or n4--->n3 ---->n2 -----> n1 ? I was asked to calculate the wavelengths of emitted photons. But is there only 1 such wavelength? 4? how many?