# Fundamental Physical Constants

Name Symbol Value Values given below are from the CODATA 1998 recommended by the National Institute of Standards and Technology of United States (NIST). Values contain the (uncertainty) in the last two decimal places given in brackets. Values that do not have this uncertainty listed are exact.For example: mu = 1.66053873(13) x 10-27 kg mu = 1.66053873 x 10-27 kg Uncertainty in mu = 0.00000013 x 10-27 kg Atomic Mass Unit mu 1.66053873(13) x 10-27 kg Avogadro's Number NA 6.02214199(47) x 1023 mol-1 Bohr Magneton B 9.27400899(37) x 10-24 J T-1 Bohr Radius ao 0.5291772083(19) x 10-10 m Boltzmann's Constant k 1.3806503(24) x 10-23 J K-1 Compton Wavelength c 2.426310215(18) x 10-12 m Deuteron Mass md 3.34358309(26) x 10-27 kg Electric Constant o 8.854187817 x 10-12 F m-1 Electron Mass me 9.10938188(72) x 10-31 kg Electron-Volt eV 1.602176462(63) x 10-19 J Elementary Charge e 1.602176462(63) x 10-19 C Faraday Constant F 9.64853415(39) x 104 C mol-1 Fine Structure Constant 7.297352533(27) x 10-3 Hartree Energy Eh 4.35974381(34) x 10-18 J Hydrogen Ground State 13.6057 eV Josephson Constant Kj 4.83597898(19) x 1014 Hz V-1 Magnetic Constant o 4 x 10-7 Molar Gas Constant R 8.314472(15) J K-1 mol-1 Natural Unit of Action 1.054571596(82) x 10-34 J s Newtonian Constant of Gravitation G 6.673(10) x 10-11 m3 kg-1 s-2 Neutron Mass mn 1.67492716(13) x 10-27 kg Nuclear Magneton n 5.05078317(20) x 10-27 J T-1 Planck Constant h 6.62606876(52) x 10-34 J sh = 2 Planck Length lp 1.6160(12) x 10-35 m Planck Mass mp 2.1767(16) x 10-8 kg Planck Time tp 5.3906(40) x 10-44 s Proton Mass mP 1.67262158(13) x 10-27 kg Rydberg Constant RH 10 9.73731568549(83) x 105 m-1 Stefan Boltzmann Constant 5.670400(40) x 10-8 W m-2 K-4 Speed of Light in Vacuum c 2.99792458 x 108 m s-1 Thompson Cross Section e 0.665245854(15) x 10-28 m2 Wien Displacement Law Constant b 2.8977686(51) x 10-3 m K

Source:

CODATA Recommended Values of the Fundamental Physical Constants: 1998
by Peter J. Mohr and Barry N. Taylor
National Institute of standards and Technology, Gaithersburg, MD 20899-8401

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