Homework Help: Quick question about Rydberg Constant Equations

1. Feb 11, 2005

scissors

So I have the equation

1/lambdamn = R(1/(n^2) - 1/(m^2))

Where m > n, and lambda is the energy emitted by a photon from m going down to n. And I have to get show that this formula can be explained by

1.) Requiring that light occurs in quanta

2.) And to get a formula for Energy in terms of R.

I had previously derived this forumula

E = - e^2 / 4*pi*eo*an + n^2*(hbar)/^2/2m*an

where a is the radius of the electron orbit, n will be 1 for our purposes, etc. How do I go about getting an equation for part 2...and how do I even begin part 1?

Any help is appreciated, thanks!

2. Feb 11, 2005

da_willem

It maybe helps to notice that lambda is not the energy but the wavelength of the emitted photon.

3. Feb 11, 2005

dextercioby

How did u get that formula,exactly...?I mean,expressed as a sum of 2 terms,what does each stand for...?

Daniel.

4. Feb 11, 2005

Galileo

Conservation of energy requires:

$$\frac{hc}{\lambda}=E_n-E_m$$
where $E_n>E_m$.

Use the expression for the nth energy to find R.

5. Feb 11, 2005

scissors

But what equations do I have for En and Em?

6. Feb 11, 2005

da_willem

Do you know Bohrs model of the hydrogen atom?