Question

Write Bohr's postulates for the hydrogen atom model.

Answer 1

First Postulate: Electron revolves round the nucleus in discrete circular orbits called stationary orbits without emission of radiant energy. These orbits are called stable orbits or non-radiating orbits.

Second Postulate: Electrons revolve around the nucleus only in orbits in which their angular momentum is an integral multiple of $h/2\pi$.

Third Postulate: When an electron makes a transition from one of its non-radiating orbits to another of lower energy, a photon is emitted having energy equal to the energy difference between the two states. The frequency of the emitted photon is then given by, $v=\frac{E_i-E_f}{h}$