| Quantity | Symbol | Value |
|---|
| Atomic mass unit | u | 1.660 538 782(83)×10−27kg |
| Avogadro’s number | NA | 6.02214076×1023reciprocal mole(mol–1) |
| Bohr magneton | μB=eℏ2me | 9.274 009 15(23)×10−24J/T |
| Bohr radius | a0=ℏ2mee2ke | 5.291 772 085 9(36)×10−11m |
| Boltzmann’s constant | kB=RNA | 1.380649×10–23joule per kelvin(J⋅K–1) |
| Compton wavelength | λC=hmec | 2.426 310 217 5(33)×10−12m |
| Coulomb constant | ke=14πε0 | 8.987 551 788...×109N⋅m2/C2(exact) |
| Deuteron mass | md | 3.343 583 20(17)×10−27kg |
| Electron mass | me | 9.109 382 15(45)×10−31kg |
| Electron volt | eV | 1.602 176 487(40)×10−19J |
| Elementary charge | e | 1.602176634×10−19C |
| Gas constant | R | 8.314 472(15)J/mol⋅K |
| Gravitational constant | G | 6.674 28(67)×10−11N⋅m2/kg2 |
| Neutron mass | mn | 1.674 927 211(84)×10−27kg |
| Nuclear magneton | μn=eℏ2mp | 5.050 783 24(13)×10−27J/T |
| Permeability of free space | μ0 | 4π×10−7T⋅m/A(exact) |
| Permittivity of free space | ε0=1μ0c2 | 8.854 187 817...×10−12C2/N⋅m2(exact) |
| Planck’s constant | h
ℏ=h2π | 6.62607015×10−34kg⋅m2⋅s–1 |
| Proton mass | mp | 1.672 621 637(83)×10−27kg |
| Rydberg constant | RH | 1.097 373 156 852 7(73)×107m−1 |
| Speed of light in vacuum | c | 2.997 924 58×108m/s(exact) |
TableC1 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⋅fm
ℏc=1973eV⋅Å=197.3eV⋅nm=197.3MeV⋅fm
kee2=14.40eV⋅Å=1.440eV⋅nm=1.440MeV⋅fm
kBT=0.02585eV atT=300K
