Physical Constants
A selection of commonly used fundamental constants.
| Constant | Symbol | Value | 
| Unified atomic mass | mu | 1.66043 × 10-27 kg | 
| Mass of hydrogen atom | mH | 1.67343 × 10-27 kg | 
| Mass of neutron | mn | 1.67482 × 10-27 kg | 
| Mass of proton | mp | 1.67252 × 10-27 kg | 
| Mass of electron | me | 9.1091 × 10-31 kg | 
| Charge of electron | e | 1.60210 × 10-19 C | 
| Avagadro's number | NA | 6.02252 × 1023 mol-1 | 
| Gas constant | R | 8.3143 JK-1mol-1 | 
| Standard temperature and pressure | s.t.p. | 273.15 K, 101325 Nm-2 | 
| Molar volume at s.t.p. | Vm | 2.24136 × 10-2 m3mol-1 | 
| Planck constant | h | 6.6256 × 10-34 Js | 
| Boltzmann constant | k | 1.38054 × 10-19 C | 
| Faraday constant | F | 9.64870 × 104 Cmol-1 | 
| Stefan-Boltzmann constant | σ | 5.6704 × 10-8 Wm-2K-4 | 
| Velocity of light in vacuum | c0 | 2.99792 × 108 ms-1 |