Question #01511

1 Answer
Nov 17, 2017

Three spectral lines
4 => 3 transition is in Infrared spectrum #(lamda = 1890 nm)#
4 => 2 transition is in the Visible spectrum #(lamda=488nm)#, and
4 => 1 transition in the Ultra Violet Spectrum #(lamda= 97nm)#.

Explanation:

One can calculate the wavelength of each transition using the equation
#1/lamda# = #R_H##(1/n_f^2 - 1/n_i^2)#; #R_H = 109,678cm^-1#.

4 => 3 transition
=> #1/lamda# = #109,678cm^-1(1/(3)^2 - (1/(4)^2)# = #5265cm^-1#

=> #lamda# = #1.89xx10^-4cm# = 1890 nm (IR wavelength)

4 => 2 transition
=> #1/lamda# = #109,678cm^-1(1/(2)^2 - (1/(4)^2)# = #2051cm^-1#

=> #lamda# = #4.88xx10^-5cm# = 488 nm (Visible wavelength)

4 => 1 transition
=> #1/lamda# = #109,678cm^-1(1/(1)^2 - (1/(4)^2)# = #5265cm^-1#

=> #lamda# = #9.73xx10^-6cm# = 97 nm (UV wavelength)
http://www.cyberphysics.co.uk/topics/light/emspect.htm