Question

what are the various postulates of bohrs model of atom how could bohrs model explain the existence of so many lines in the spectrum of hydrogen

Answer 1

Dear Student,


The postulates of Bohr's model:-
1) Electrons revolve around the nucleous only in certain permissible circular orbits , also called shells.
2) Each orbit is associated with a definite energy.
3) The energy of an electron remains constant as long asit revolves in a given orbit.
4) When an electron absorbs energy, it jumps from a low -energy level to a high-energy level.
5) But, an electron at higher energy level is unstable . so, it jumps from higher energy level to lower energy level and gives out energy
6) Energy is emitted or absorbed when an electron moves from one level to another. Thus by absorbing one particular quantum of energy, the electron will jump from a energy level 1 to 2 or 2 to 3. It is then said to be in excited state. The quantum of energy absorbed in each case is equal to the difference in energies of the two levels. An electron cannot have an energy that would place it in between the two permissible orbits.
When an electron moves from a higher energy (E ₂ ) orbit to a lower energy (E ₁ ) orbit, the energy (ΔE = E ₂ – E ₁ ) is emitted in the form of a photon of frequency v such that ΔE=E ₂ -E ₁ =hv