The planetary model of the atom pictures electrons orbiting the atomic nucleus much as planets orbit the Sun. In this model, you can view hydrogen, the simplest atom, as having a single electron in a circular orbit 1.06×10-10 m in diameter.
(a) If the average speed of the electron in this orbit is known to be 2.20×106 m/s, calculate the number of revolutions per second it makes about the nucleus.
(b) What is the electron’s average velocity?
The formula to be used is
Rearraging the formula–solving for the distance
Substituting the given values
We know the total distance traveled in 1 sec. We know that in 1 revolution, the total distance is
Therefore, the total number of revolutions traveled in 1 second is
In one complete revolution, the electrons will go back to its original position. Thus, there is no net displacement. Therefore,