Radius of nth Bohr Orbit
### Formula:
$$r_n=\frac{n^2h^2}{4\pi^2me^2kZ}$$
### Terminologies:
- $$r_n$$ β Radius of nth orbit.
- n β Principal quantum number.
- h β Planck's constant.
- m β Mass of electron.
- e β Charge of electron.
- k β Electrostatic constant.
- Z β Atomic number.
### Usage:
- Used to calculate radius of electron orbit in hydrogen-like species.