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Constants

Name Symbol Value
Boltzmann constant kB 1.380 6503(24) x 10-23 J K-1
Planck constant h 6.626 068 76(52) x 10-34 J s
Planck contant / 2 1.054 571 596(82) x 10-34 J s
Elementary charge e 1.602 176 462(63) x 10-19 C
Avogadro number NA 6.022 141 99(47) x 1023 mol-1
Speed of light c 299 792 458 m s-1
Permeability of vacuum mu0 12.566 370 x 10-7 N
Permittivity of vacuum epsilon0 8.854 187 817 x 10-12 F m-1
Fine structure constant alpha 7.297 352 533(27) x 10-3
Gravitational constant G 6.673(10) x 10-11 m3 kg-1 s-2
Acceleration due to gravity g 9.806 65 m s-2
Electron rest mass me 9.109 381 88(72) x 10-31 kg
Proton rest mass mp 1.672 621 58(13) x 10-27 kg
Neutron rest mass mn 1.674 927 16(13) x 10-27 kg
Charge-to-mass ratio for electron e / me 1.758 820 174(71) x 1011 C kg-1
Atomic mass unit amu 1.660 538 73(13) x 10-27 kg
Electron radius re 2.817 940 285(31) x 10-15 m
Gas constant (R = NA kB) R 8.314 472(15) J mol-1 K-1
Molar volume Vmol 22.413 996(39) x 10-3 m3 mol-1
Compton wavelength of the electron lambdac 2.426 310 215(18) x 10-12 m
Stefan-Boltzmann constant 5.670 400(40) x 10-8 W m-2 K-4
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