From: physics. nist. gov/constants Fundamental Physical Constants- Complete listing Relative std ydberg constant a-mec/2h 10973731.568549(83) 7.6×10=12 3289841960368(25)×1015Hz 7.6×10- 2.17987190(17)×10 Roohc in ev 13.60569172(53) 3.9×10-8 Bohr radius a/4xR∞=4x∈0h2/me2ao 0.5291772083(19)×10-10m 3.7×10-9 Hartree energy e2/4TE0a0=2Roohc 435974381(34)×10-18J 78×10-8 In h/2me3.636947516(27)×10-4ev 27.2113834(1 quantum of circulation s-17.3×10-9 h/m 7273895032(53)×10-4m2s-17.3×10 Fermi coupling constant GF/(hc)31.166391)×10-5 86×10-6 weak mixing angled ow(on-shell scheme) sinew 0.2224(19) 87×10-3 electron mass 910938188(72)×10-31kg 79×10-8 in u, me= Ar(e)u(electron relative atomic mass times u) 54857991012)×10-4 2.1×10 energy equivalent 818710414(64)×10 7.9×10 n mev 0.510998902(21) Mev 4.0×10-8 electron -muon mass ratio ml/m14.8363210(15) 3.0×10-8 electron-tau mass ratio me/mx28755547)×10-4 1.6×10-4 electron-proton mass ratio me/mp5.446170232(12)×10-4 2.1×10 electron-neutron mass ratio 5438673462(12)×10-4 electron-deuteron mass ratio 27244371170(58)×10-4 2.1×10- electron to alpha particle mass ratio me/ml1.3709335611(29)×10-4 electron charge to mass quotient 1758820174(71)× Ckg 40×10-8 electron molar mass Name M(e),M5.485799110(12)×10-7 kg mol-12.1×10 Compton wavelength h/mec 2426310215(8)×10-12m 73×10-9 λC/2x=aao=a2/4xR NC 3861592642(28)×10 7.3×10-9 classical electron radius a ao 2817940285(31)×10-15m 1.1×10=8 Thomson cross section(8T/3)r2 0665245854(15)×10-28m 2.2×10 electron magnetic moment 928476362(37)×10-26JT-140×10-8 to bohr magneton ratio He/uB 11596521869(41) to nuclear magneton ratio /u -1838.2819660(39) 2.1×10 electron magnetic moment anomaly luel/uB-1 11596521869(41)×10-3 3.5×10-9 electron g-factor -2(1+ae) 2.0023193043737(82) 4.1×10-12 electron-muon letic moment ratio e/pp206766972063) 3.0×10-8 Page 2 Journal of Physical and Chemical Reference Data, Vol. 28, No. 6, 1999 and Reviews of Modern Physics, Vol. 72, No. 2, 2000From: physics.nist.gov/constants Fundamental Physical Constants — Complete Listing Relative std. Quantity Symbol Value Unit uncert. ur Rydberg constant α2mec/2h R∞ 10 973 731.568 549(83) m−1 7.6 × 10−12 R∞c 3.289 841 960368(25) × 1015 Hz 7.6 × 10−12 R∞hc 2.179 871 90(17) × 10−18 J 7.8 × 10−8 R∞hc in eV 13.605 691 72(53) eV 3.9 × 10−8 Bohr radius α/4π R∞ = 4π02 /mee2 a0 0.529 177 2083(19)× 10−10 m 3.7 × 10−9 Hartree energy e2 /4πε0a0 = 2R∞hc = α2mec2 Eh 4.359 743 81(34)× 10−18 J 7.8 × 10−8 in eV 27.211 3834(11) eV 3.9 × 10−8 quantum of circulation h/2me 3.636 947 516(27)× 10−4 m2 s−1 7.3 × 10−9 h/me 7.273 895 032(53)× 10−4 m2 s−1 7.3 × 10−9 Electroweak Fermi coupling constantc GF/(c)3 1.166 39(1) × 10−5 GeV−2 8.6 × 10−6 weak mixing angled θW (on-shell scheme) sin2 θW = s2 W ≡ 1 − (mW/mZ)2 sin2 θW 0.2224(19) 8.7 × 10−3 Electron, e− electron mass me 9.109 381 88(72)× 10−31 kg 7.9 × 10−8 in u, me = Ar(e) u (electron relative atomic mass times u) 5.485 799 110(12)× 10−4 u 2.1 × 10−9 energy equivalent mec2 8.187 10414(64) × 10−14 J 7.9 × 10−8 in MeV 0.510 998 902(21) MeV 4.0 × 10−8 electron-muon mass ratio me/mµ 4.836 332 10(15) × 10−3 3.0 × 10−8 electron-tau mass ratio me/mτ 2.875 55(47) × 10−4 1.6 × 10−4 electron-proton mass ratio me/mp 5.446 170 232(12) × 10−4 2.1 × 10−9 electron-neutron mass ratio me/mn 5.438 673 462(12)× 10−4 2.2 × 10−9 electron-deuteron mass ratio me/md 2.724 437 1170(58) × 10−4 2.1 × 10−9 electron to alpha particle mass ratio me/mα 1.370 933 5611(29) × 10−4 2.1 × 10−9 electron charge to mass quotient −e/me −1.758 820 174(71) × 1011 C kg−1 4.0 × 10−8 electron molar mass NAme M(e), Me 5.485 799 110(12)× 10−7 kg mol−1 2.1 × 10−9 Compton wavelength h/mec λC 2.426 310 215(18) × 10−12 m 7.3 × 10−9 λC/2π = αa0 = α2 /4π R∞ žC 386.159 2642(28)× 10−15 m 7.3 × 10−9 classical electron radius α2a0 re 2.817 940 285(31) × 10−15 m 1.1 × 10−8 Thomson cross section (8π/3)r 2 e σe 0.665 245 854(15)× 10−28 m2 2.2 × 10−8 electron magnetic moment µe −928.476 362(37)× 10−26 J T−1 4.0 × 10−8 to Bohr magneton ratio µe/µB −1.001 159 6521869(41) 4.1 × 10−12 to nuclear magneton ratio µe/µN −1 838.281 9660(39) 2.1 × 10−9 electron magnetic moment anomaly |µe|/µB − 1 ae 1.159 652 1869(41) × 10−3 3.5 × 10−9 electron g-factor −2(1 + ae) ge −2.002 319 3043737(82) 4.1 × 10−12 electron-muon magnetic moment ratio µe/µµ 206.766 9720(63) 3.0 × 10−8 Page 2 Source: Peter J. Mohr and Barry N. Taylor, CODATA Recommended Values of the Fundamental Physical Constants: 1998, Journal of Physical and Chemical Reference Data, Vol. 28, No. 6, 1999 and Reviews of Modern Physics, Vol. 72, No. 2, 2000