# Homework Help: Revolutions in a Bohr Model

1. Apr 12, 2005

### Jacob87411

According to the Bohr theory, how many revolutions will an electron make in the first excited state of hydrogen if the lifetime in that state is 10^-8?

Basically do I find the speed of the that the electron moves in this excited state then get the distance that a revolution is and divide it by the time?

2. Apr 12, 2005

### dextercioby

Find the period for the first orbit and then use $10^{-8}s$ and the following reasoning

1 revolution---------------------------->T

x revolutions---------------------------->10^{-8}s

Daniel.

Last edited: Apr 12, 2005
3. Apr 13, 2005

### Jacob87411

Right. When finding the period do I take velocity to be the speed of light?

4. Apr 13, 2005

### dextercioby

No,the velocity on the first orbit

$$v_{I}=\alpha c$$

,where $\alpha$ is the fine structure constant...

Daniel.