# Table of Constants

Fundamental constants from NIST Physics Lab :
| Name | Symbol | Value | Units | Relative Uncertainty |
| Speed of light (in vacuum) | $c$ | $299\ 792\ 458$ | $\mathrm {m} \ \mathrm {s} ^{-1}$ | (exact) |
| Magnetic constant | $\mu _{0}$ | $4\pi \times 10^{-7}\approx$ | $\mathrm {N} \ \mathrm {A} ^{-2}$ | (exact) |
| Electric constant | $\epsilon _{0}$ | $1/(\mu _{0}c^{2})\approx$ | $\mathrm {F} \ \mathrm {m} ^{-1}$ | (exact) |
| Newtonian gravitational constant | $G$ | $6.674\ 2(10)\times 10^{-11}$ | $\mathrm {m} ^{3}\ \mathrm {kg} ^{-1}\ \mathrm {s} ^{-2}$ | $1.5\times 10^{-4}$ |
| Plank's constant | $h$ | $6.626\ 069\ 3(11)\times 10^{-34}$ | $\mathrm {J} \ \mathrm {s}$ | $1.7\times 10^{-7}$ |
| Elementary charge | $e$ | $1.602\ 176\ 53(14)\times 10^{-19}$ | $\mathrm {C}$ | $8.5\times 10^{-8}$ |
| Mass of the electron | $m_{e}$ | $9.109\ 382\ 6(16)\times 10^{-31}$ | $\mathrm {kg}$ | $1.7\times 10^{-7}$ |
| Mass of the proton | $m_{p}$ | $1.672\ 621\ 71(29)\times 10^{-27}$ | $\mathrm {kg}$ | $1.7\times 10^{-7}$ |
| Mass of a neutron | $m_{n}$ | | | |
| Fine structure constant | $\alpha =e^{2}/(2\epsilon _{0}hc)$ | $7.297\ 352\ 568(24)\times 10^{-3}$ | dimentionless | $3.3\times 10^{-9}$ |
| Molar gass constant | $R$ | $8.314\ 472(15)$ | $\mathrm {J} \ \mathrm {mol} ^{-1}\ \mathrm {K} ^{-1}$ | $1.7\times 10^{-6}$ |
| Boltzmann's constant | $k$ | $1.380\ 650\ 5(24)$ | $\mathrm {J} \ \mathrm {K} ^{-1}$ | $1.8\times 10^{-6}$ |
| Avogadro's number | $N_{A}$ | $6.022\ 141\ 5(10)\times 10^{23}$ | $\mathrm {mol} ^{-1}$ | $1.7\times 10^{-7}$ |
| Rydberg constant | $R_{\infty }$ | $10\ 973\ 731.568\ 525(73)$ | $\mathrm {m} ^{-1}$ | $6.6\times 10^{-12}$ |
| Atmosphere | $\mathrm {atm}$ | $101325$ | | (exact) |
| Electronvolt | $\mathrm {eV}$ | $1.60\times 10^{-19}$ | | |
| Bohr radius | $a_{0}$ | $5.292\times 10^{-11}$ | | |
| Coulomb's constant | $k$ | ${\frac {1}{4\pi \epsilon _{0}}}\approx$ | | |
| Faraday constant | $F$ | $e\times N_{A}\approx$ | | |
| Gravitational acceleration on Earth | $g$ | | | |
| Mass of the Earth | | | | |
| Mass of the Moon | | | | |
| Mean radius of the Earth | | | | |
| Mean radius of the Moon | | | | |
| Dirac's Constant | $\hbar$ | | | |
| Speed of sound in air at STP | | | | |
| Unified Atomic Mass Unit | $u$ | | | |
| Vacuum Permittivity | $\epsilon _{0}$ | | | |
* 1 Atmosphere Pressure (1 atm) : 1.0 × 10$^5$ N/m$^2$ = 1.0 × 10$^5$ Pa
* 1 Electron Volt (1 eV) : 1.60 × 10$^{−19}$ J
* Bohr radius (a$_0$) : 5.292 × 10$^{−11}$ m
* Coulomb's Law Constant (k) : 1/(4 π ε$_0$) = 9.0 × 10$^9$ N·m$^2$/C$^2$
* Faraday constant (F) : 96,485 C·mol$^{−1}$
* Gravitational accelaration (g) : 9.80665 m·s$^{-2}$
* Mass of a neutron (m$_n$) : 1.67495 × 10$^{−27}$ kg
* Mass of Earth : 5.98 × 10$^{24}$ kg
* Mass of the Moon : 7.35 × 10$^{22}$ kg
* Mean radius of Earth : 6.37 × 10$^6$ m
* Mean radius of the Moon : 1.74 × 10$^6$ m
* Dirac's Constant ($\hbar$) : $h/(2\pi )$ = 1.05457148 × 10$^{−34}$ J·s
* Speed of sound in air at STP : 3.31 × 10$^2$ m/s
* Unified Atomic Mass Unit (u) : 1.66 × 10$^{−27}$ kg
* Vacuum Permittivity (ε$_0$) : 8.85 × 10$^{−12}$ C$^2$/(N·m$^2$)
| Item | Proton | Neutron | Electron |
| Mass | 1 | 1 | Negligible |
| Charge | +1 | 0 | -1 |
| Spin | ${\frac {1}{2}}$ | ${\frac {1}{2}}$ | ${\frac {1}{2}}$ |

# See Also
## Wiki-links

* Wikipedia Article

## External Links

* NIST Physics Lab