Question

calculate the wave length of the emitted radiation when an electron jumps back from 5th orbit to 3rd orbit.

Answer 1

Let the wavelength be x and a=5,b=3
then
1/x =- 109677 {(1/a^2)-(1/b^2)}
1/x =-109677(1/25-1/9)
x=1.2 *10^(-4)