In 1912 Bohr joined Rutherford. He realized that Rutherford's model ... energy levels (orbits) in a quantum fashion, that is, without ever existing in an in-between state. Thus when an atom ...
It came when the one electron of the hydrogen atom transitioned from the 2P 1/2 energy level to the 2S 1/2 level ... increasing circular orbits of the Bohr atom.) Conventional quantum mechanics ...