Physical Constants
atomic mass constant Avogadro constant ["A00543-5","A00543-0"]Bohr magneton Bohr radius Boltzmann constant ["B00695-3"]electron rest mass elementary charge ["E02032-1"]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 ["P04685-2"]proton magnetic moment proton rest mass radiation constants Rydberg constant speed of light in a vacuum ["S05854-0","S05854-2"]Stefan–Boltzmann constant