Physics Constants
This table contains a number of physical constants often used in physics and engineering.
Quantity | Symbol | Value | SI Units | Cgs Units |
Velocity of light | c | 2.9979250 | 108 m/sec | 1010 cm/sec |
Free space permittivity | eo | 8.8541 | 10-12 F / m | 10-14 F / cm |
Free space permeability | mo | 1.2566 | 10-6 H / m | 10-8 H / cm |
Fine-structure constant | a | 7.297351 | 10-3 | 10-3 |
Electron charge | e | 1.6021917 | 10-19 C | 10-20 emu |
Planck’s constant | h | 6.626196 | 10-34 J-sec | 10-27 erg-sec |
Avogadro’s number | N | 6.022169 | 1026 kmole-1 | 1023 mole-1 |
Atomic mass unit | amu | 1.660531 | 10-27 kg | 10-24 gm |
Electron rest mass | me | 9.109558 | 10-31 kg | 10-28 gm |
Proton rest mass | Mp | 1.672614 | 10-27 kg | 10-24 gm |
Neutron rest mass | Mn | 1.674920 | 10-27 kg | 10-24 gm |
Proton / electron mass ratio | Mp / me | 1836.109 | ||
Electron charge / mass ratio | e / me | 1.7588028 | 1011 C / kg | 107 emu / gm |
Faraday constant | F | 9.648670 | 107 C / kmole | 103 emu / mole |
Rydberg constant | R∞ | 1.09737312 | 107 m-1 | 105 cm-1 |
Boltzman constant | K | 1.3807 | 10-23 J / K | 10-16 erg / K |
Stefan-Boltzman constant | s | 5.671 | 10-8 W / m2 K4 | 10-5 W / cm2 K4 |
Gravitational constant | g | 9.8067 | kg m / s2 | 105 gm cm / s2 |
Loschmidt constant | no | 2.6868 | 1025 m-3 | 1019 cm-3 |
Bohr radius | ao | 5.2917715 | 10-11 m | 10-9 cm |
Classical electron radius | ro | 2.817939 | 10-15 m | 10-13 cm |
Standard atmosphere | atm | 1.0132 x 105 Pa | 1.0125 x 106 erg / cm3 |