What are Bohr's postulates

to directory mode

Area of ​​Expertise - Quantum physics

In the context of the atomic model developed by Niels Bohr in 1913 (see Bohr's atomic model), the underlying postulates (Postulate - as a starting point, as a necessary, indispensable prerequisite for a theory, an assumption serving a train of thought, a thesis that has not been proven or cannot be proven) on the movement of the electrons in the electron shell of an atom:

  1. There are circular orbits in the atom on which the electrons - contrary to the laws of classical physics - rotate without radiation. However, not all classically possible, but only discrete paths with certain energies En are allowed. The atom is in the lowest energy state (in the ground state) when the electron revolves on the orbit with the smallest permitted radius (principal quantum number n = 1, Bohr radius). The orbits further out correspond to higher (excited) energy states of the atom.
  2. By supplying a corresponding energy, the excitation energy, the electron can be brought onto a path with a larger radius. This excited state is not stable - the electron falls back from the energetically higher to an energetically lower path. The energy difference ΔE between the starting and ending tracks is emitted in the form of electromagnetic radiation (light) of a certain frequency (see Bohr's frequency relationship).