Bohr radius

Bohr radius
Symbola0 or rBohr
Named afterNiels Bohr
Approximate values (to three significant digits)
SI units5.29×10−11 m (52.9 pm)

The Bohr radius () is a physical constant, approximately equal to the most probable distance between the nucleus and the electron in a hydrogen atom in its ground state. It is named after Niels Bohr, due to its role in the Bohr model of an atom. Its value is 5.29177210544(82)×10−11 m.