What does a bohr model of iron look like?
Hydrogen the simplest of all elements, was investigated most extensively both experimentally and theoretically. As long ago as 1885, Balmer succeeded in obtaining a simple relationship among the wave numbers of the lines in the visible region of the hydrogen spectrum.
The first quantitative correct derivation of the Balmer formula on the basis of an atomic model was given by Bohr (1913), in his theory of the hydrogen atom. Those theory has played such an important role in the development of atomic physics that even though it has been modified and extended by the later developments in quantum mechanics, it will be worthwhile to present the original simplified theory.
In 1913, Niels Bohr proposed a model for the hydrogen atom which retained the earlier nuclear model of Rutherford but made further stipulations as to the behavior of the electron. A dramatic explanation of the Rydberg spectral expression resulted.