What and how did Niels Bohr develop the atomic model further?
The Bohr model was published in 1913; he proposed that the electrons of an atom orbit in circles around a small nucleus. Furthermore, he proposed that only those orbits for which the angular momentum of the electrons were integral multiples of h/2pi were allowed. Thus his model, allowed classical ‘planetary’ orbits but was also quantised. His second proposal was that no electron radiated energy as long as it remained in its allotted orbit. Thus, in the Bohr model electrons only radiated energy when they moved between orbits and this energy was quantised. Plainly, this was a very simple but for all that useful model. It could predict the principle spectra of hydrogen but could not deal with line splitting, which is observed in spectrographic analysis with high resolving power. This explanation requires quantisation of the angular momentum and elliptical orbits. Next, some of the spectra suggest that electrons have quantised spin. With these modifications: an elliptical orbits, quantised
