| Symbol | Value and Unit | quantity |
|---|---|---|
| u | 1.6605402x10-27 kg 1.49242072x10-10 J c-2 931.49432 MeV | Atomic mass unit (amu) |
| NA | 6.0221367x1023 mol-1 6.0221367x1026 kmol-1 | Avogadro's number |
| e | 2.7182818 | Base of natural logarithms |
| k | 1.3800 J K-1 | Boltzmann constant (R/NA) |
| p | 3.1415927 | Circumference to diameter ratio |
| C | 8.987551787x109 N m2 kg-2 | Coulomb constant |
| qe | 1.60217733x10-19 C/e 4.80653199x10-10 esu/e | Electric charge per electron |
| F | 96485.309 C/mol 2.894559x1014 esu | Faraday constant |
| G | 8.987551787x109 N m2 C-2 | Gravitational constant |
| R | 8.314510 J mole-1 K-1 0.08205 l atm mole-1 K-1 | Ideal gas constant |
| h | 6.6260755x10-34 J s 6.6260755x10-27 erg s | Planck's constant |
| me | 9.1093897x10-31 kg 5.48579903x10-4 u 0.510999 MeV | Rest mass of electron |
| mp | 1.6726231x10-27 kg 1.007276470 u 938.2723 MeV | Rest mass, proton |
| mH | 1.67353404x10-27 kg 1.00782505 u 938.7833 MeV | Rest mass, hydrogen |
| mn | 1.6749286x10-27 kg 1.008664904 u 939.56536 MeV | Rest mass, neutron |
| c | 299,792,458 m s-1 2.997925x1010 cm/s | Velocity of light |
| RH | 109677.60 cm-1 | Rydberg constant for H |