Fundamental Physical Constants Name and Symbol Value atomic mass unit (amu) 1.6605402 × 10−27 kg Avogadro’s number 6.0221367 × 1023 mol−1 Boltzmann’s constant (k) 1.380658 × 10−23 J K−1 charge-to-mass ratio for electron (e/me) 1.75881962 × 1011 C kg−1 electron charge (e) 1.60217733 × 10−19 C electron rest mass (me) 9.1093897 × 10−31 kg Faraday’s constant (F) 9.6485309 × 104 C mol−1 gas constant (R) 8.205784 × 10−2 L atm mol−1 K−1 = 8.314510 J mol−1 K−1 molar volume of an ideal gas, 1 atm, 0 °C 22.41409 L mol–1 molar volume of an ideal gas, 1 bar, 0 °C 22.71108 L mol–1 neutron rest mass (mn) 1.6749274 × 10−27 kg Planck’s constant (h) 6.6260755 × 10−34 J s proton rest mass (mp) 1.6726231 × 10−27 kg Rydberg constant (R) 1.0973731534 × 107 m−1 = 2.1798736 × 10−18 J speed of light (in vacuum) (c) 2.99792458 × 108 m s−1