# Table of Constants

Fundamental constants from NIST Physics Lab
Name Symbol Value Units Relative Uncertainty
Speed of light (in vacuum) ${\displaystyle c}$  ${\displaystyle 299\ 792\ 458}$  ${\displaystyle \mathrm {m} \ \mathrm {s} ^{-1}}$  (exact)
Magnetic constant ${\displaystyle \mu _{0}}$  ${\displaystyle 4\pi \times 10^{-7}\approx }$  ${\displaystyle \mathrm {N} \ \mathrm {A} ^{-2}}$  (exact)
Electric constant ${\displaystyle \epsilon _{0}}$  ${\displaystyle 1/(\mu _{0}c^{2})\approx }$  ${\displaystyle \mathrm {F} \ \mathrm {m} ^{-1}}$  (exact)
Newtonian gravitational constant ${\displaystyle G}$  ${\displaystyle 6.674\ 2(10)\times 10^{-11}}$  ${\displaystyle \mathrm {m} ^{3}\ \mathrm {kg} ^{-1}\ \mathrm {s} ^{-2}}$  ${\displaystyle 1.5\times 10^{-4}}$
Plank's constant ${\displaystyle h}$  ${\displaystyle 6.626\ 069\ 3(11)\times 10^{-34}}$  ${\displaystyle \mathrm {J} \ \mathrm {s} }$  ${\displaystyle 1.7\times 10^{-7}}$
Elementary charge ${\displaystyle e}$  ${\displaystyle 1.602\ 176\ 53(14)\times 10^{-19}}$  ${\displaystyle \mathrm {C} }$  ${\displaystyle 8.5\times 10^{-8}}$
Mass of the electron ${\displaystyle m_{e}}$  ${\displaystyle 9.109\ 382\ 6(16)\times 10^{-31}}$  ${\displaystyle \mathrm {kg} }$  ${\displaystyle 1.7\times 10^{-7}}$
Mass of the proton ${\displaystyle m_{p}}$  ${\displaystyle 1.672\ 621\ 71(29)\times 10^{-27}}$  ${\displaystyle \mathrm {kg} }$  ${\displaystyle 1.7\times 10^{-7}}$
Mass of a neutron ${\displaystyle m_{n}}$
Fine structure constant ${\displaystyle \alpha =e^{2}/(2\epsilon _{0}hc)}$  ${\displaystyle 7.297\ 352\ 568(24)\times 10^{-3}}$  dimentionless ${\displaystyle 3.3\times 10^{-9}}$
Molar gass constant ${\displaystyle R}$  ${\displaystyle 8.314\ 472(15)}$  ${\displaystyle \mathrm {J} \ \mathrm {mol} ^{-1}\ \mathrm {K} ^{-1}}$  ${\displaystyle 1.7\times 10^{-6}}$
Boltzmann's constant ${\displaystyle k}$  ${\displaystyle 1.380\ 650\ 5(24)}$  ${\displaystyle \mathrm {J} \ \mathrm {K} ^{-1}}$  ${\displaystyle 1.8\times 10^{-6}}$
Avogadro's number ${\displaystyle N_{A}}$  ${\displaystyle 6.022\ 141\ 5(10)\times 10^{23}}$  ${\displaystyle \mathrm {mol} ^{-1}}$  ${\displaystyle 1.7\times 10^{-7}}$
Rydberg constant ${\displaystyle R_{\infty }}$  ${\displaystyle 10\ 973\ 731.568\ 525(73)}$  ${\displaystyle \mathrm {m} ^{-1}}$  ${\displaystyle 6.6\times 10^{-12}}$
Atmosphere ${\displaystyle \mathrm {atm} }$  ${\displaystyle 101325}$  (exact)
Electronvolt ${\displaystyle \mathrm {eV} }$  ${\displaystyle 1.60\times 10^{-19}}$
Bohr radius ${\displaystyle a_{0}}$  ${\displaystyle 5.292\times 10^{-11}}$
Coulomb's constant ${\displaystyle k}$  ${\displaystyle {\frac {1}{4\pi \epsilon _{0}}}\approx }$
Faraday constant ${\displaystyle F}$  ${\displaystyle e\times N_{A}\approx }$
Gravitational acceleration on Earth ${\displaystyle g}$
Mass of the Earth
Mass of the Moon
Mean radius of the Earth
Mean radius of the Moon
Dirac's Constant ${\displaystyle \hbar }$
Speed of sound in air at STP
Unified Atomic Mass Unit ${\displaystyle u}$
Vacuum Permittivity ${\displaystyle \epsilon _{0}}$
• 1 Atmosphere Pressure (1 atm) : 1.0 × 105 N/m2 = 1.0 × 105 Pa
• 1 Electron Volt (1 eV) : 1.60 × 10−19 J
• Bohr radius (a0) : 5.292 × 10−11 m
• Coulomb's Law Constant (k) : 1/(4 π ε0) = 9.0 × 109 N·m2/C2
• Faraday constant (F) : 96,485 C·mol−1
• Gravitational accelaration (g) : 9.80665 m·s-2
• Mass of a neutron (mn) : 1.67495 × 10−27 kg
• Mass of Earth : 5.98 × 1024 kg
• Mass of the Moon : 7.35 × 1022 kg
• Mean radius of Earth : 6.37 × 106 m
• Mean radius of the Moon : 1.74 × 106 m
• Dirac's Constant (${\displaystyle \hbar }$ ) : ${\displaystyle h/(2\pi )}$  = 1.05457148 × 10−34 J·s
• Speed of sound in air at STP : 3.31 × 102 m/s
• Unified Atomic Mass Unit (u) : 1.66 × 10−27 kg
• Vacuum Permittivity (ε0) : 8.85 × 10−12 C2/(N·m2)
 Item Proton Neutron Electron Mass 1 1 Negligible Charge +1 0 -1 Spin ${\displaystyle {\frac {1}{2}}}$ ${\displaystyle {\frac {1}{2}}}$ ${\displaystyle {\frac {1}{2}}}$