Question: 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 1.06Ã-10âˆ'10 m in diameter. (a) If the average speed of the electron in this orbit is known to be 2.20Ã-106 m/s , calculate the number of revolutions per second it makes about the nucleus. (b) What is the electron's average velocity?