## Quantum world objective again

Science questions not covered in Chem 14A and 14B. Try to limit questions to chemistry (inorganic chemistry, physical chemistry, organic chemistry, biophysical chemistry, biochemistry, materials science, environmental chemistry).

Claire_Kim_2F
Posts: 67
Joined: Wed Sep 30, 2020 10:02 pm

### Quantum world objective again

I was also confused on the objective about knowing how to calculate electron transitions for the H-atom spectrum using the En equation. Does this mean the En equation only works for hydrogen atoms? Am I able to use the rydberg equation for hydrogen atoms or do I have to use the En equation?

Jordi M 2I
Posts: 144
Joined: Wed Sep 30, 2020 9:40 pm

### Re: Quantum world objective again

Yes the equation $E_{n} = -\frac{hR}{n^{2}}$ works for determining the energy at a specific n level for hydrogen atoms ONLY.
The Rydberg equation I believe you are talking about is v = - R [ 1/n^2 -1/n^2] - (the first n is the initial energy level and the second is the final, sorry my equation editor was weird) - This equation is only useful in determining the frequency of the emitted or absorbed light or for finding the energy level n that the electron was de-excited to or from. It cannot directly tell you the total energy at a specific level n. This equation is also only for hydrogen atoms.

Claire_Kim_2F
Posts: 67
Joined: Wed Sep 30, 2020 10:02 pm

### Re: Quantum world objective again

With this v = - R [ 1/n^2 -1/n^2] equation couldnt you use it to find the frequency and then convert it into E= frequency times plancs constant to figure out the exact energy?

Jordi M 2I
Posts: 144
Joined: Wed Sep 30, 2020 9:40 pm

### Re: Quantum world objective again

Claire_Kim_2F wrote:With this v = - R [ 1/n^2 -1/n^2] equation couldnt you use it to find the frequency and then convert it into E= frequency times plancs constant to figure out the exact energy?

Yes but it’s a two step process. That’s what I meant when I said the equation doesn’t give you the energy directly.