# Question #98328

Nov 10, 2017

The Bohr's model for the hydrogen atom is based on the Bohr postulates.

The postulates are,

1) An electron revolves around the atomic nucleus in certain allowed orbits without emission of an ]y radiant energy (contrary to predictions of the classical EM theory).

2) Only those orbits are allowed for which the angular momentum of the electron is an integral multiple of $\frac{h}{2 \pi}$,

$L = \frac{n h}{2 \pi}$ where $n = 1 , 2 , 3 , 4 , \ldots .$ and $h$ is the Planck's constant.

3) An electron in an orbit of energy ${E}_{1}$ can make a transition a level of energy ${E}_{2}$ and in doing so, it emits a single photon of frequency,

$\nu = \frac{{E}_{1} - {E}_{2}}{h}$

The entire theory of Bohr's model is based on these postulates and on the fact that the Coulombic attraction between electrons and the nucleus provides the centripetal force for revolution of the electron.