## Fall 2014 Quiz 1 Preparation

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

Shirley Wong 2E
Posts: 22
Joined: Fri Sep 25, 2015 3:00 am

### Fall 2014 Quiz 1 Preparation

I'm struggling with #10 on the Fall 2014 Quiz 1 Preparation in the workbook. The answers at the end says to use the Bohr equation, but I don't really understand the work shown with it. Can someone clarify it for me?

Kim Vu 2G
Posts: 29
Joined: Fri Sep 25, 2015 3:00 am

### Re: Fall 2014 Quiz 1 Preparation

The answers in the workbook is telling you to use the Bohr equation which is En=-2.18*10^18 (z^2/n^2). The 2.18*10^18 is just a constant for the equation, the z is for the number of protons in the nucleus and n is the quantum level. Because the frequency was given, you can use it to find the change in energy with the equation E=hv which should be 7.56x10^20 joules. Then use the equation change of energy=final energy-initial energy with the 7.56x10^20 joules being the change of energy and because the number of proton in hydrogen a nucleus is one, use (1/4^2)-(1/n^2)*(2.18*10^18). After setting up the equation, it's just algebraic methods to solve for the variable n and the level n should be is 6.

Kiara1F
Posts: 64
Joined: Fri Sep 25, 2015 3:00 am

### Re: Fall 2014 Quiz 1 Preparation

Which constant is the2.18

Chem_Mod
Posts: 17659
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 404 times

### Re: Fall 2014 Quiz 1 Preparation

Based on the numbers listed below, it seems the constant is -hR where h is Planck's constant and R is the Rydberg constant. The atomic hydrogen spectra problems are based on the Bohr model of the atom.