De Broglie thought that it might be possible to express the "location" of the electron around the nucleus by treating it as a special kind of wave: a "standing wave". Such a wave reinforces itself as it travels.
This fits in nicely with Planck's idea that different wavelengths have different energies and with Bohr's idea that there were only certain allowed energies (i.e., de Broglie wavelengths) for the electron in the hydrogen atom.
While everyone was dreaming about little negative particles circling around tiny nuclei, in 1927 Davisson and Germer--in a classic experiment--were diffracting electron beams! Particles were behaving like waves!
So, in some cases, the electron appeared to behave as if it were a wave (EMR) rather than a particle. This ultimate "split-personality" of the electron would help to "explain" away many of its peculiar properties. BUT HOW DOES THAT RELATE TO ATOMIC STRUCTURE?????