Write three postulates of Bohr. Mention two limitation of Bohr model.

Explanation

Postulates :
(1) The electrons revolve only in certain orbits called stationary orbits without the emission of radiant
energy
(2) The angular momentum of an electron in the stationary orbit is an integral multiple of `(h)/(2pi)`
`L=(nh)/(2pi)`
Where, `n=1,2,3,..`
(principal quantum number).
h= Plank.s costant.
(3) An electron does not radiate energy in its stationary orbits. An electron emits energy only when it jumps from outer orbit to inner orbit. If E, and E, are the energies of an electron in the inner orbit (lower energy level) and outer orbit (higher energy level) respectively, then energy of emitted photon (radiation) is given by.
`E=E_(2)-E_(1)`