Wednesday, May 31, 2017

What is the frequency of the light emitted by atomic hydrogen with m = 8 and n = 12? (The Rydberg constant is R =1.097 x 107 m-1, c = 3.00 x 108 m/s) I gotz 2.86*10^13Hz dunno if correct. Show steps please.

  
 
The Rydberg equation is
1/λ = RZ2(1/n12 - 1/n22)
where λ is the wavelength of the photon emitted
R is the Rydberg constant
Z is the atomic number which in this case is 1 since we are dealing with the hydrogen atom
n1 is the same as m which is 8
n2 is  12
So we work out the wavelength of the emitted photon as follows:
 1/λ  = 1.097 x 10^7 (1/8^2 - 1/12^2)
1/λ  = 1.097 x 10^7 x 0.00868
1/λ  =9.522 x 10^4 m^-1
λ= 1.050 x 10^-5m
We then use  f= c/λ to calculate the frequency
              f  = 3.00 x 10^8/1.050 x 10^-5
              f =  2.86 x 10^13 Hz
The wavelength and frequency that we just found tell us that the transition emits energy in the infra-red region of the electromagnetic spectrum. So one would not expect to see a spectral line for a transition from m =8 to m = 12
 
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch6/bohr.html

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