| Constant | Symbol | Numerical value |
|---|---|---|
| Gravitational constant | G | 6.6720·10-11 N·m2·kg-2 |
| Speed of light in vacuum | c | 2.99792458·108 m·s-1 |
| Magnetic constant | μ0 | 4π·10-7H·m-1 = 1.25663706144·10-6H·m-1 |
| Electric constant | ε0 = (μ0c2)-1 | 8.85418782·10-12 F·m-1 |
| Planck constant | h |
6.626176·10-34 J·s |
| Rest mass of the electron | me | 9.109534·10-31 kg 5.4858026·10-4 amu |
| Rest energy of the electron | mec2 | 0.5110034 MeV |
| Rest mass of the proton | mp | 1.6726485·10-27 kg 1.007276470 amu |
| Rest energy of the proton | mpc2 | 938.2796 MeV |
| Rest mass of the neutron | mn | 1.6749543·10-27 kg 1.008665012 amu |
| Rest energy of the neutron | mnc2 | 939.5731 MeV |
| Ratio of the proton mass to the electron mass | mp/me | 1836.15152 |
| Charge of the electron (absolute value) | e | 1.6021892·10-19 C 4.803242·10-10 CGSE units |
| Ratio of the electron charge to its mass | e/me | 1.7588047·1011 C·kg-1 |
| Bohr magneton | μB | 9.274078·10-24 J·T-1 |
| Nuclear magneton | μN | 5.050824·10-24 J·T-1 |
| Magnetic moment of the neutron in nuclear magnetons | μn/μN | 1.91315 |
| Magnetic moment of the proton in nuclear magnetons | μp/μN | 2.7928456 |
| Atomic mass unit (10-3 kg·mol-1)/NA | amu | 1.6605655(86)·10-27 kg |
| Masses of atoms in amu: hydrogen deuterium helium-4 |
1H 2H 4He |
1.007825036 2.014101795 4.002603267 |
| Avogadro constant | NA | 6.022045·1023 mol-1 |
| Faraday constant | F = NAe | 96484.56 C·mol-1 |
| Molar gas constant | R | 8.31441 C·mol-1·K-1 |
| Volume of a mole of an ideal gas under normal conditions (1 atm, T0 = 273.15 K) | Vm | 22.41383·10-3 m3·mol-1 |
| Boltzmann constant | k = R/NA | 1.380662·10-23 J·K-1 |
| Fine structure constant | α 1/α |
0.072973506 137.03604 |
| Rydberg constant | R∞ | 10973731.77 m-1 |
| Radius of the first Bohr orbit | a0 | 0.52917706·10-10 m |
| Classical radius of the electron | re | 2.8179380·10-15 m |
| Josephson ratio | 2e/h | 4.835939·1014 Hz·V-1 |
| Magnetic flux quantum | Φ0 = h/2e | 2.0678506·10-15 Wb |
| Energy equivalents: amu 1 electronvolt |
|
931.5016 MeV 1.6021892·10-19 J |
| 1 eV/k 1 eV/hc 1 eV/h |
11604.50 K 8065.479 cm-1 2.4179696·1014 Hz |