### test 2 #4

Posted:

**Sun Apr 29, 2018 11:33 pm**On test 2 on question we had to find the energy difference but were not given then levels like n=? so how would we go about doing this?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=17&t=31225

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Posted: **Sun Apr 29, 2018 11:33 pm**

On test 2 on question we had to find the energy difference but were not given then levels like n=? so how would we go about doing this?

Posted: **Sun Apr 29, 2018 11:43 pm**

I had trouble with that one too for the same reason. I assumed it was from n=1 to n=2, but wasn't sure.

The formula I used was the En= -hR/n^2 which I believe is the same as the V= R((1/n1^2)-(1/n2^2))

The formula I used was the En= -hR/n^2 which I believe is the same as the V= R((1/n1^2)-(1/n2^2))

Posted: **Mon Apr 30, 2018 9:35 pm**

The energy lost from the transition is turned into the energy of the emitted photon. Thus, the energy difference is same as the energy of a photon. So, just needed to calculate E = hv.

Posted: **Wed May 02, 2018 7:57 pm**

Just to clarify, is the equation En = -hR/ n^2 only used for calculating the change in energy levels for a hydrogen atom? I used this equation on the test, and I wanted to clarify that that was why this was wrong, since the question was asking about a multi-electron atom.

Posted: **Sun May 06, 2018 11:23 am**

I believe E=-hR/n^2 is only valid for hydrogen, yet this equation was not needed on the test.