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### E=R(1/n-1/n)?

Posted: Sun Apr 29, 2018 11:31 pm
I'm confused on how exactly Borh's equation is turned into E=R(1/n-1/n) when finding the difference in energy level?

### Re: E=R(1/n-1/n)?

Posted: Mon Apr 30, 2018 1:24 am
ΔE=Ef-Ei
En= -hR/n^2

ΔE= -hR/nf^2 - (-hR/ni^2)
ΔE= hR/ni^2 - hR/nf^2

V=R(1/ni^2 - 1/nf^2)
ΔE/h= R(1/ni^2 - 1/nf^2)
ΔE=hR(1/ni^2 - 1/nf^2)
ΔE=hR/ni^2 - hR/nf^2

### Re: E=R(1/n-1/n)?

Posted: Wed May 09, 2018 12:54 am
Are we supposed to use E= R(1/n-1/n) or E= hR/n^2 when finding the difference in energy levels?

### Re: E=R(1/n-1/n)?

Posted: Wed May 09, 2018 12:38 pm
When given two energy levels (n1,n2) or a beginning and ending energy state you can use the E=R(1/n-1/n). The other formula, E=-R(h/n^2) is used to find the energy of an electron in the nth state of a hydrogen atom specifically

### Re: E=R(1/n-1/n)?

Posted: Wed May 09, 2018 8:49 pm
I am not 100% sure, but I think the equation R(1/n^2-1/n^2) is used to find the frequency, where the first one is initial and the second one is final because when deriving it you would get a negative final plus a positive initial, therefore it can switch places to make it a little simpler. (This was in my notes from discussion)

### Re: E=R(1/n-1/n)?

Posted: Thu May 10, 2018 9:06 pm
E=R(1/n2^2-1/n1^2) is the equation to specifically find the change in energy. The E= -hR/n^2 is for one specific energy level

### Re: E=R(1/n-1/n)?

Posted: Thu May 10, 2018 10:22 pm
The book says Frequency = R(1/n2^2-1/n1^2)

### Re: E=R(1/n-1/n)?

Posted: Fri May 11, 2018 10:47 am
If a problem states energy was emitted would the final answer be negative and if the problem asks energy was absorbed would the final answer be positive?