# Fundamental constants

The following table gives the values of the majority of fundamental constants needed in a school Physics course. The units for each are given together with the symbol for some.

 Avogadro mass unit 932 MeV or 1.66x10-27 kg Avogadro's number 6.02x1023 mol-1 Boltzmann's constant 1.38x10-23 JK-1 Electron charge 1.602x10-19 C Electron mass 9.11x10-31 kg or 0.000 549 u Energy conversions 1 u = 1.66x10-27 kg = 1.492x10-10 J = 931 MeV Mass of alpha particle 4.001 506 u Mass of helium atom 4.002 603 u Mass of proton 1.007 276 u Mass of neutron 1.008 665 u Mass of hydrogen (1H) atom 1.007 825 u Mean value of go for the Earth 9.81 ms-2 Molar gas constant 8.31 mol-1K-1 Permeability of free space (mo) 4px10-7 Hm-1 Permittivity of free space (eo) 8.85x10-12 Fm-1 Planck's constant (h) 6.63x10-34 Js Specific charge of the electron (e/m) 1.76x1011 Ckg-1 Speed of electromagnetic radiation in free space 2.997 925x108 ms-1 Stefan's constant (s) 5.7x10-8 Wm2K-4 Universal constant of gravitation (G) 6.67x10-11 Nm2kg-2