Physics Study Guide/Physics constants

Commonly Used Physical Constants

Uncertainty should be read as 1.234(56) = 1.234$\pm$0.056

Name	Symbol	Value	Units	Relative Uncertainty
Speed of light (in vacuum)	c	$299\ 792\ 458$	$\mathrm{m}\ \mathrm{s}^{-1}$	(exact)
Magnetic Constant	μ0	$4\pi\times10^{-7}\approx12.566\ 370\ 6\times10^{-7}$	$\mathrm{N}\ \mathrm{A}^{-2}$	(exact)
Electric Constant	$\epsilon_0 = 1/\left( \mu_0c^2 \right)$	$\approx8.854\ 187\ 817\times10^{-12}$	$\mathrm{F}\ \mathrm{m}^{-1}$	(exact)
Newtonian Gravitaional Constant	G	$6.674\ 2(10)\times10^{-11}$	$\mathrm{m}^3\ \mathrm{kg}^{-1}\ \mathrm{s}^{-2}$	$1.5\times10^{-4}$
Plank's Constant	h	$6.626\ 069\ 3(11)\times10^{-34}$	$\mathrm{J}\ \mathrm{s}$	$1.7\times10^{-7}$
Elementary charge	e	$1.602\ 176\ 53(14)\times10^{-19}$	C	$8.5\times10^{-8}$
Mass of the electron	me	$9.109\ 382\ 6(16)\times10^{-31}$	kg	$1.7\times10^{-7}$
Mass of the proton	mp	$1.672\ 621\ 71(29)\times10^{-27}$	kg	$1.7\times10^{-7}$
Fine structure constant	$\alpha=\frac{e^2}{4 \pi \epsilon_0 \hbar c}$	$7.297\ 352\ 568(24)\times10^{-3}$	dimensionless	$3.3\times10^{-9}$
Molar gass constant	R	$8.314\ 472(15)$	$\mathrm{J}\ \mathrm{mol}^{-1}\ \mathrm{K}^{-1}$	$1.7\times10^{-6}$
Boltzman's constant	k	$1.380\ 650\ 5(24)\times10^{-23}$	$\mathrm{J}\ \mathrm{K}^{-1}$	$1.8\times10^{-6}$
Avogadro's Number	NA	$6.022\ 141\ 5(10)\times10^{23}$	mol − 1	$1.7\times10^{-7}$
Rydberg constant	$R_\infty$	$10\ 973\ 731.568\ 525(73)$	m − 1	$6.6\times10^{-12}$
Standard acceleration of gravity	g	$9.806\ 65$	$\mathrm{m}\ \mathrm{s}^{-2}$	defined
Atmospheric pressure	atm	$101\ 325$	Pa	defined
Bohr Radius	$a_0\$	$0.529\ 177\ 208\ 59(36)\times10^{-10}\$	$\mathrm{m}\$	$6.8\times10^{-10}$
Electron Volt	eV	$1.602\ 176\ 53(14)\times10^{-19}$	J	$8.7\times10^{-8}$

To Be Merged Into Table

This list is prepared in the format

• Constant (symbol) : value

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• Coulomb's Law Constant (k) : 1/(4 π ε₀) = 9.0 × 10⁹ N·m²/C²
• Faraday constant (F)  : 96,485 C·mol⁻¹
• Mass of a neutron (m_n) : 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 ($\hbar$) : h / (2π) = 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

Item	Proton	Neutron	Electron
Mass	1	1	Negligible
Charge	+1	0	-1

See Also

Wiki-links

• Wikipedia Article

External Links

• NIST Physics Lab