Bohr's Atomic Model

Question 1

Postulates

Answer 1

1) Electron moves around nucleus on a path with fixed radius (orbit)
2) Energy of electron does not change in orbit. Only changes when energy absorbed (low to high) or emitted (high to low)
3) Frequency of radiation absorbed or emitted during transition of 2 states :-

Frequency = (E2 - E1)/h. (E1 and E2 lower and higher state respectively)

4) Angular momentum of electron quantised. Stationary state :-

me vr = (nXh)/2pi

me - mass of electron
v - velocity
r - radius
n = 1, 2, 3, ….

Question 2

Bohr’s Atomic Theory for H atom

Answer 2

1) Stationary states numbered (n) = 1, 2, 3, ….

2) Radii of stationary orbits :-
r = n^2 ao
ao = 52.9 pm (Bohr orbit [first stationary state])

3) Energy of electron in stationary state :-
En = -Rh (1/n^2). where, n =1, 2, …….

4) Applicable to ions with one e-, LI+, etc.