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University Physics Volume 1

C | Fundamental Constants

University Physics Volume 1C | Fundamental Constants
Quantity Symbol Value
Atomic mass unit u 1.660 538 782(83)×10−27kg931.494 028(23)MeV/c21.660 538 782(83)×10−27kg931.494 028(23)MeV/c2
Avogadro’s number NANA 6.02214076×1023reciprocal mole(mol–1)6.02214076×1023reciprocal mole(mol–1)
Bohr magneton μB=eℏ2meμB=eℏ2me 9.274 009 15(23)×10−24J/T9.274 009 15(23)×10−24J/T
Bohr radius a0=ℏ2mee2kea0=ℏ2mee2ke 5.291 772 085 9(36)×10−11m5.291 772 085 9(36)×10−11m
Boltzmann’s constant kB=RNAkB=RNA 1.380649×10–23joule per kelvin(J⋅K–1)1.380649×10–23joule per kelvin(J⋅K–1)
Compton wavelength λC=hmecλC=hmec 2.426 310 217 5(33)×10−12m2.426 310 217 5(33)×10−12m
Coulomb constant ke=14πε0ke=14πε0 8.987 551 788...×109N·m2/C2(exact)8.987 551 788...×109N·m2/C2(exact)
Deuteron mass mdmd 3.343 583 20(17)×10−27kg2.013 553 212 724(78)u1875.612 859MeV/c23.343 583 20(17)×10−27kg2.013 553 212 724(78)u1875.612 859MeV/c2
Electron mass meme 9.109 382 15(45)×10−31kg5.485 799 094 3(23)×10−4u0.510 998 910(13)MeV/c29.109 382 15(45)×10−31kg5.485 799 094 3(23)×10−4u0.510 998 910(13)MeV/c2
Electron volt eV 1.602 176 487(40)×10−19J1.602 176 487(40)×10−19J
Elementary charge e 1.602176634×10−19C1.602176634×10−19C
Gas constant R 8.314 472(15)J/mol·K8.314 472(15)J/mol·K
Gravitational constant G 6.674 28(67)×10−11N·m2/kg26.674 28(67)×10−11N·m2/kg2
Neutron mass mnmn 1.674 927 211(84)×10−27kg1.008 664 915 97(43)u939.565 346(23)MeV/c21.674 927 211(84)×10−27kg1.008 664 915 97(43)u939.565 346(23)MeV/c2
Nuclear magneton μn=eℏ2mpμn=eℏ2mp 5.050 783 24(13)×10−27J/T5.050 783 24(13)×10−27J/T
Permeability of free space μ0μ0 4π×10−7T·m/A(exact)4π×10−7T·m/A(exact)
Permittivity of free space ε0=1μ0c2ε0=1μ0c2 8.854 187 817...×10−12C2/N·m2(exact)8.854 187 817...×10−12C2/N·m2(exact)
Planck’s constant h
 ℏ=h2πℏ=h2π		 6.62607015×10−34kg·m2·s–11.05457182×10−34kg·m2·s–16.62607015×10−34kg·m2·s–11.05457182×10−34kg·m2·s–1
Proton mass mpmp 1.672 621 637(83)×10−27kg1.007 276 466 77(10)u938.272 013(23)MeV/c21.672 621 637(83)×10−27kg1.007 276 466 77(10)u938.272 013(23)MeV/c2
Rydberg constant RHRH 1.097 373 156 852 7(73)×107m−11.097 373 156 852 7(73)×107m−1
Speed of light in vacuum c 2.997 924 58×108m/s(exact)2.997 924 58×108m/s(exact)
Table C1 Fundamental Constants Note: These constants are the values recommended in 2006 by CODATA, based on a least-squares adjustment of data from different measurements. The numbers in parentheses for the values represent the uncertainties of the last two digits.

Useful combinations of constants for calculations:

hc=12,400eV·Å=1240eV·nm=1240MeV·fmhc=12,400eV·Å=1240eV·nm=1240MeV·fm

ℏc=1973eV·Å=197.3eV·nm=197.3MeV·fmℏc=1973eV·Å=197.3eV·nm=197.3MeV·fm

kee2=14.40eV·Å=1.440eV·nm=1.440MeV·fmkee2=14.40eV·Å=1.440eV·nm=1.440MeV·fm

kBT=0.02585eV atT=300KkBT=0.02585eV atT=300K

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