Writer Bohr's postulates for the hydrogen atom model.

Explanation

(i)Bohr.s first postulate was that an electron in an atom could resolve in certain stable orbits without the emission of radiant energy.
According to this postulate each atom has certain definite stable orbits in which it can exists and each possible state has definite total energy . These are called the stationary states of the atom.
(ii)Bohr.s second postulate defines these stable orbits. This postulate states that the electrons resolves around the nucleus only in those orbits for which the angular momentum is integral multiple of `h/(2pi)` where h is the plank.s constant.
(iii)Bohr.s third postulates states that an electron might make a transition from one of its specified non-radiating orbits to another of lower energy . When it does so a photon is emitted having energy equal to the energy difference between the initial and final states.
The frequency of the emitted photon is then given by
`hv=E_r-E_i rArr v=(E_f-E_i)/h`