## Confusion with problem 1.57 [ENDORSED]

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

Anna De Schutter - 1A
Posts: 66
Joined: Wed Feb 21, 2018 3:01 am

### Confusion with problem 1.57

Hi!

Problem 1.57 says: "Lines in the Balmer series of the hydrogen spectrum are observed at 656.3, 486.1, 434.0, and 410.2 nm. What is the wavelength of the next line in the series?"

I thought because in the Balmer series we are starting at n=2, that the next line in the series would be n=6. However, the solutions manual says "For the Balmer series n1=2, so the fifth line in the spectrum should be n2=7." Isn't the fifth line n=6 in the Balmer series?

Thank you! :)
Anna De Schutter - section 1A

AnnaYan_1l
Posts: 96
Joined: Fri Apr 06, 2018 11:05 am
Been upvoted: 1 time

### Re: Confusion with problem 1.57

Hi, Anna! I had the same issue with this problem originally. It is important to remember that Balmer series means that the electron transitions from a higher energy level to n=2.

So, we can assume that:
656.3 nm is a transition from n=3 to n=2
486.1 nm is a transition from n=4 to n=2
434.0 nm is a transition from n=5 to n=2
410.2 nm is a transition from n=6 to n=2
So, the next line in the series would be a transition from n=7 to n=2.

(Then, you can use the equation $\Delta E = \left ( \frac{-hR}{2^{2}} \right ) - \left ( \frac{-hR}{7^{2}} \right )$ to solve for the energy released. Finally, you would solve for wavelength.)

I hope that helps!

Anna De Schutter - 1A
Posts: 66
Joined: Wed Feb 21, 2018 3:01 am

### Re: Confusion with problem 1.57  [ENDORSED]

That makes a lot of sense! Thank you so much! :)

Joussie Camacho 4I
Posts: 33
Joined: Tue Oct 02, 2018 12:16 am

### Re: Confusion with problem 1.57

Will we be tested on the Balmer series in Test 2?

Joussie Camacho 4I
Posts: 33
Joined: Tue Oct 02, 2018 12:16 am

### Re: Confusion with problem 1.57

Will we be tested on the Balmer series in Test 2?