# Homework Help: De broglie wavelength?

1. Oct 28, 2011

### Jason265

1. The problem statement, all variables and given/known data
In the Bohr model of the hydrogen atom, if the electron is in the second orbit with a radius of 2.12 Å. What is the de Broglie wavelength of the electron?

2. Relevant equations

λ = 4h^2ε/me^2

3. The attempt at a solution

I found this equation hunting around online and figured out that the constant is 2 times the energy level, but I do not have all of this information. How would I solve this problem?

2. Oct 28, 2011

### dextercioby

What's the connection between the orbit and energy of the electron on that orbit ? Then the energy is simply h$\nu$ from which $\lambda$ is easily derived.