Question

Calculate the wavelength of the first line and the series limit for the Lyman series for hydrogen.(Series limit is for the case when n2=∞)

Answer 1

Paschen series:

n1 = 3 , n2 = 4 , 5 , 6 , . . . . .  

The wave number of these spectral lines could be calculated by the given equation :

⊽ = 1 / λ = R {( 1 / n1 ² ) - (1 / n2 ² )}

The Paschen series in near IR region can be calculated by following formula :

⊽ = R [ 1 / 3 ^ 2 - 1 / n2 ^ 2 ]