


The de Broglie hypothesis says the wavelength of a particle's matter wave is inversely proportional to its momentum. Therefore the smaller mass and smaller momentum of the electron means that it has a longer wavelength.
The Bohr model retains Rutherford's compact nucleus as the location of all the positive charge in an atom. The Thomson "plum pudding" model is the one that has a positively charged "pudding" surrounding the negatively charged electrons.
If the electron jumps from the n = 4 to the n = 3 level, it can then also jump from
3
2, 3
1, or
2
1. Each of those four transitions would release a photon of a unique
energy or color. Two other unique colors would result from 4
2 and
4
1 jumps, for a total of 6 unique colors.