## 7th edition HW Problem 1.A15

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

Lopez_Melissa-Dis4E
Posts: 66
Joined: Fri Sep 28, 2018 12:20 am

### 7th edition HW Problem 1.A15

Hello, can someone please explain how to solve HW Problem 1A.15 in the 7th edition of the textbook?

Elena Maneffa 1E
Posts: 33
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### Re: 7th edition HW Problem 1.A15

For a line at 102.6nm, we know that n1=1.

Then use the equation c=(wavelength)(frequency), but rearrange it to look like:

v= c/(wavelength)

So:

v=(2.998x10^8)/(102.6x10^-9) =2.922x10^15 s^-1.

We then need to find n2.

Use this equation: v=R((1/n1^2) - (1/n2^2).

Then you will get this if you rearrange:

1/n2^2 =(1/1^2) -(v/R)

(1/n2^2)=1-((2.922x10^15)/(3.29x10^15))

This is equal to o.112.

So...
(1/n2^2) =0.112.

n2^2=9

Take the square root on each side to solve for n2

n2=3.

n1=1 and n2=3.

Elena Maneffa 1E
Posts: 33
Joined: Fri Sep 28, 2018 12:27 am
Been upvoted: 1 time

### Re: 7th edition HW Problem 1.A15

Wait, actually, sorry. My TA said we can't use the equation from the book. We are supposed to use another one, so the above explanation is wrong. Sorry.