| Name and Symbol | Value |
|---|---|
| Standard acceleration due to gravity (g) | $\mathbf{\equiv}$ 9.806 65 m/s2 |
| Atomic mass unit (amu) | 1.660 5391 × 10−27 kg |
| Avogadro’s number | $\mathbf{\equiv}$ 6.022 140 76 × 1023 mol−1 |
| Boltzmann’s constant (kB) | $\mathbf{\equiv}$ 1.380 649 × 10−23 J K−1 |
| Fundamental unit of charge (e) | $\mathbf{\equiv}$ 1.602 176 634 × 10−19 C |
| Electron rest mass (me) | 9.109 383 7015 × 10−31 kg |
| Charge-to-mass ratio for electron (e/me) | 1.758 820 0109 × 1011 C kg−1 |
| Faraday’s constant (F) | $\mathbf{\equiv}$ 9.648 533 212 331 001 84 × 104 C mol−1 |
| gas constant (R) | $\mathbf{\equiv}$ 8.314 462 618 153 24 J mol−1 K−1
0.082 057 84 L atm mol−1 K−1 0.083 146 26 L bar mol−1 K−1 |
| Neutron rest mass (mn) | 1.674 927 498 × 10−27 kg |
| Planck’s constant (h) | $\mathbf{\equiv}$ 6.626 070 15 × 10−34 J s |
| Proton rest mass (mp) | 1.672 621 923 × 10−27 kg |
| Rydberg constant (R∞) | 1.097 373 156 8160 × 107 m-1 |
| Rydberg unit of energy (Ry = hcR∞) | 2.179 872 361 1035 × 10−18 J |
| Speed of light (in vacuum) (c) | $\mathbf{\equiv}$ 2.997 924 58 × 108 m s−1 |
Values from NIST Committee on Data for Science and Technology (CODATA) Recommended Values: 2018