Physical constants

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QuantitySymbolValue
permeability of vacuumμ4π x 10-7 H.m-1 (defined)
speed of light in vacuumc299 792 458 m.s-1 (defined)
permittivity of vacuumε0 = 1/μ0c028.854 187 816 ... x 10-12 F.m-1
Planck's constanth6.626 075 5(40) x 10-34 J.s
 h_strikethrough = h/2π1.054 572 66(63) x 10-34 J.s
elementary chargee1.602 177 33(49) x 10-19 C
electron rest massme9.109 389 7(54) x 10-31 kg
proton rest massmp1.672 623 1(10) x 10-27 kg
neutron rest massmn1.674 928 6(10) x 10-27 kg
atomic mass constant, (unified atomic mass unit)mu = 1u1.660 540 2(10) x 10-27 kg
Avogadro constantL, NA6.022 136 7(36) x 1023 mol-1
Boltzmann constantk1.380 658(12) x 10-23 J.K-1
Faraday constantF9.648 530 9(29) x 104 C.mol-1
gas constantR8.314 510 (70) J.K-1.mol-1
zero of the Celsius scale 273.15 K (defined)
molar volume, ideal gas, p = 1 bar, θ = 00C 22.711 08(19) L.mol-1
standard atmosphereatm101 325 Pa (defined)
fine structure constantα = μ0e2c0/2h7.297 353 08(33) x 10-3
 α-1137.035 989 5(61)
Bohr radiusa05.291 772 49(24) x 10-11 m
Hartree energyEh4.359 748 2(26) x 10-18 J
Rydberg constantRinfinity1.097 373 153 4(13) x 10-7 m-1
Bohr magnetonμB9.247 015 4(31) x 10-24 J.T-1
electron magnetic momentμe9.284 770 1(31) x 10-24 J.T-1
Lande g-factor for free electronge2.002 319 304 386(20)
nuclear magnetonμN5.050 786 6(17) x 10-27 J.T-1
proton magnetic momentμp1.410 607 61(47) x 10-26 J.T-1
proton magnetogyric ratioγp2.675 221 28(81) x 108 s-1.T-1
magnetic moment of protons in H20, μ'pμ'pB1.520 993 129(17) x 10-3
proton resonance frequency per field in H20γ'p/2π42.576 375 (13) M.Hz.T-1
Stefan-Boltzmann constantσ5.670 51(19) x 10-8 W.m-2.K-4
first radiation constantc13.741 774 9(22) x 10-16 W.m2
second radiation constantc21.438 769 (12) x 10-2 m.K
gravitational constantG6.672 59(85) x 10-11 m3.kg-1.s-2
standard acceleration of free fallgn9.80665 m.s-2 (defined)