Physical Constants
atomic mass constant Avogadro constant ["A00543-5","A00543-0"]Bohr magneton Bohr radius Boltzmann constant electron rest mass elementary charge Faraday constant fine structure constant ["F02389-0"]gas constant gravitational constant Hartree energy neutron rest mass nuclear magneton permeability of vacuum ["P04504-0"]permittivity of vacuum Planck constant proton magnetic moment proton rest mass radiation constants Rydberg constant speed of light in a vacuum Stefan–Boltzmann constant