3. The Bohr model of the atom

Rutherford's planetary model of the atom was understood in terms of classical electrodynamics. This model could in principle explain the occurrence of radiation, since in Maxwell's theory, light is emitted by accelerated charges, hence by the electrons in orbit. (Note that acceleration is required in a circular orbit) At the same time this causes a contradiction in the theory, since the decelerated electrons, while emitting light, would continuously loose energy, collaps with the nucleus and make the atoms unstable. So the quest was for a theory explaining the stability of the atom and the existence of stationary states.
Bohr made a break with classical physics by adopting notions from quantum theory and by simply postulating the existence of stationary states.

The assumptions of Bohr, stated in his original paper were simply:
Within this model Bohr could give a Mathematical derivation of the Rydberg formula.

A few comments on Bohr's model:

Extension of the Bohr-model
Explanation of characteristic X-rays in the Bohr-model

Last change: 18 February 2001