# Atomic physics: sodium D-line transition missing 2 pi

1. Jun 9, 2007

### El Hombre Invisible

1. The problem statement, all variables and given/known data

Find the wavelength of the sodium transition $$3p^{1},^{2}P -> 3s^{1},^{2}S$$

2. Relevant equations

$$E_{n,l} = -\frac{hcR}{(n - d(n,l))^{2}}$$

d(3,s) = 1.374
d(3,p) = 0.884

$$\lambda = \frac{\hbar c}{\Delta E}$$

3. The attempt at a solution

Plugging the numbers in ain't even close. However, I've found another equation that works:

$$\frac{1}{\lambda} = -R[\frac{1}{(n_{i} - d_{i}(n,l))^{2}} - \frac{1}{(n_{f} - d_{f}(n,l))^{2}}]$$

but since E is proportional to $$\hbar$$ and the RHS on the top equation just to h... where did the $$2\pi$$ go..?

Last edited: Jun 9, 2007
2. Jun 9, 2007

### El Hombre Invisible

'Sokay. Just realised $$\lambda = \frac{hc}{\Delta E}$$ not $$\frac{\hbar c}{\Delta E}$$. Knew it would be something stupid.