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wilson_chem90
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Homework Statement
The hydrogen spectrum contains a blue line with a wavelength of 434 nm. Photons of blue light are emitted when hydrogens electron drops from the fifth energy level to a lover energy level. What is the lower energy level?
Homework Equations
En = 13.6 eV/n^2
E = hc/lambda
The Attempt at a Solution
First I'm going to find E.
E = hc/lambda
= (6.63 x 10^-34 J s)(3.00 x 10^8 m/s) / (4.34 x 10^-7 m)
= 4.583 x 10^-19 J
(1.60 x 10^-19 eV/J) x (4.583 x 10^-19 J)
= 2.86 eV
Next i tried 2 different approaches, I am not sure either is correct though. I used En = -(13.6eV/n^2) - (-13.6eV/n^2) and i just used En = -(13.6eV/n^2)
1st approach:
En = -(13.6eV/n^2) - (-13.6eV/n^2)
I rearranged this equation to be n^2 = 2(13.6eV)/En5^2 (i'm pretty sure that's incorrect)
so n^2 = 2(13.6 eV)/2.86(25)
n = sqrt(0.38041958)
n = 0.62
2nd approach:
En = -(13.6eV/n^2)
Now i rearranged this equation to be n^2 = En + 13.6eV
= 2.86eV + 13.6eV
n = sqrt16.46 eV
= 4.06
So I am pretty sure my problem lies within rearranging the equations. Any suggestions? thanks