### 1.57 Homework Conceptual

Posted:

**Tue Oct 04, 2016 5:23 pm**Hi,

For question 57 on the homework, involving lines in the Balmer series, it says in the solutions manual that "n[1]=2 so the fifth line in the spectrum should be n[2]=7. Then you plug into the Rydberg equation and find the fifth wavelength of the fifth line. What I dont understand is why you get [2]=7. Shouldnt it be equal to 6? N1=2, N2=3, N=5 and N6=6? Also when you plug into the Rydberg equation, why is the answer positive? Why is it that the form of the equation V=R(1/n1^2-1/n2^2) does not have a negative but in the formula E=-hr/n^2 does have a negative?

For question 57 on the homework, involving lines in the Balmer series, it says in the solutions manual that "n[1]=2 so the fifth line in the spectrum should be n[2]=7. Then you plug into the Rydberg equation and find the fifth wavelength of the fifth line. What I dont understand is why you get [2]=7. Shouldnt it be equal to 6? N1=2, N2=3, N=5 and N6=6? Also when you plug into the Rydberg equation, why is the answer positive? Why is it that the form of the equation V=R(1/n1^2-1/n2^2) does not have a negative but in the formula E=-hr/n^2 does have a negative?