Emission transitions in the Paschen series end at orbit n = 3 and start from orbit n and can be represeted as v = 3.29×1015(Hz) [1/32–1/n2]



Q.55:- Emission transitions in the Paschen series end at orbit n = 3 and start from orbit n and can be represeted as v = 3.29×1015(Hz) [1/32–1/n2] Calculate the value of n if the transition is observed at 1285 nm. Find the region of the spectrum.

 

 

Answer:-



ν = c/λ = 3.0×10ms-1/1285×10-9 m = 3.29×1015 (1/3 1/n2)
⇒ 1/n= 1/9 – (3.0×10ms-1/1285×10-9 m)×(1/3.29×1015) = 0.111-0.071 = 0.04 = 1/25
⇒ n= 25
⇒ n = 5
The radiation corresponding to 1285 nm lies in the infrared region.