• 2019: The angular velocity of the electron is given by

$$\omega = \frac{2\pi}{T}$$

where $T$ is the period of revolution. The period of revolution is given by

$$T = \frac{2\pi r}{v}$$

where $r$ is the radius of the orbit and $v$ is the speed of the electron. Substituting this into the equation for angular velocity, we get

$$\omega = \frac{2\pi r}{v} \frac{v}{2\pi r} = \frac{v}{r}$$

The speed of the electron is given by

$$v = \frac{2\pi e^2}{nh}$$

where $e$ is the charge of the electron, $h$ is Planck’s constant, and $n$ is the principal quantum number. Substituting this into the equation for angular velocity, we get

$$\omega = \frac{2\pi e^2}{nh} \frac{nh}{2\pi r} = \frac{e^2}{2r}$$

Substituting the values for