## Post Assessment Question

H-Atom ($E_{n}=-\frac{hR}{n^{2}}$)

Posts: 41
Joined: Wed Nov 15, 2017 3:01 am

### Post Assessment Question

42. An excited hydrogen atom emits light with a frequency of 1.14 x 1014 Hz to reach the energy level n = 4. In what principle quantum level did the electron begin?

Can anyone explain the steps needed to solve this problem? I'm having trouble starting because only one n value was given.

Kuldeep Gill 1H
Posts: 44
Joined: Fri Apr 06, 2018 11:02 am
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### Re: Post Assessment Question

Hi so you can use the equation V=R((1/n^2)-(1/n^2)) and plug-in frequency for V and plug-in rydberg's constant and then plug in 4 into the first n^2 since that is the final energy level then you would just solve for the second n value which would be your initial quantum level

the other way you could do this is to solve for energy using E=h*v and after you get the energy plug it into E= -hR/n^2 + hR/n^2 and then plug in 4 for the first n^2 and then again solve for the second n value which would be your initial quantum level. Hope that helps!