# Formula Bohr Model Radius    Velocity    Principal quantum number

Unit
The quantized radius of the orbit of an electron in the $$\class{red}{n}$$-th state in the framework of the Bohr model.

## Velocity

Unit
The quantized velocity of the electron in the $$\class{red}{n}$$-th state in the framework of the Bohr model.

## Principal quantum number

Unit
The principal quantum number $$\class{red}{n} = 1, 2, 3, ...$$ numbers the discrete energy states of an electron in the atom.

## Reduced Planck's constant

Unit
Reduced Planck's constant is a physical constant (of quantum mechanics) and has the value: $$\hbar ~=~ \frac{h}{2\pi} ~=~ 1.054 \,\cdot\, 10^{-34} \, \text{Js}$$.

## Electron mass

Unit
The rest mass of an electron is a physical constant with the value: $$m_{\text e} ~=~ 9.1 ~\cdot~ 10^{-32} \, \mathrm{kg}$$