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

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

danielruiz1G
Posts: 62
Joined: Fri Apr 06, 2018 11:04 am

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

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?

Briana Lopez 4K
Posts: 44
Joined: Wed Nov 22, 2017 3:01 am

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

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

Sonia Aronson 1B
Posts: 30
Joined: Fri Apr 06, 2018 11:01 am

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

Are we supposed to use E= R(1/n-1/n) or E= hR/n^2 when finding the difference in energy levels?

Posts: 30
Joined: Fri Apr 06, 2018 11:03 am

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

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

KristinaNguyen_1A
Posts: 30
Joined: Fri Apr 06, 2018 11:04 am

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

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)

hannahtweedy
Posts: 29
Joined: Tue Nov 21, 2017 3:00 am

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

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

Kuldeep Gill 1H
Posts: 44
Joined: Fri Apr 06, 2018 11:02 am
Been upvoted: 1 time

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

The book says Frequency = R(1/n2^2-1/n1^2)

Jocelyn Fermin1J
Posts: 49
Joined: Tue Nov 14, 2017 3:01 am

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

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?