5 Shortcomings of Bohr's model

Many quantitative results did not agree with experiment. The most important shortcomings:

1. It dealt mainly with hydrogen, the simplest atom. It explained only its spectrum, and failed to explain the spectrum of any other element, even helium with only two electrons.
2. The electron was treated purely as a negative material particle; its wave properties were ignored.
3. It assumed that the position and the speed of the electron can be determined precisely at the same time, which is practically impossible (Heisenberg).
4. Bohr's equations treat the electron as moving in a circular plane, so the hydrogen atom would be flat (planar); atoms are known to be three-dimensional.

These shortcomings led scientists to continue the search that produced the modern atomic theory.