Physical Constants
Quantity Symbol, equation Value
speed of light in vacuum c 299 792 458 m/s
Planck constant h 6.626 0693(11) x 10-34 J s
electron charge e 1.602 176 53(14) x 10-19 C
electron mass me 0.510 998 918(44) MeV/c2 = 9.109 3826(16) x 10-31 kg
proton mass mp 938.272 029(80) MeV/c2 = 1.672 621 71(29) x 10-27 kg
unified atomic mass unit (u) (mass 12C atom)/12 931.494 043(80) MeV/c2 = 1.660 538 86(28) x 10-27 kg
permittivity of free space ε0 = 1/μ0c2 8.854 187 817 … x 10-12 F m-1
permeability of free space μ0 4π x 10-7 N A-2 = 12.566 370 614 … x 10-7 N A-2
Boltzmann constant k 1.380 6505(24) x 10-23 J K-1 = 8.617 343(15) x 10-5 eV K-1
Avogadro constant NA 6.022 1415(10) x 1023 mol-1