# physical constants, 20 Jan 10

299 792 458 m·s-1 	defined speed of light in vacuum 	c 
6.67428(67)×10-11 m3·kg-1·s-2 	1.0 × 10-4 Newtonian constant of gravitation 	G 
6.626 068 96(33) × 10-34 J·s 	5.0 × 10-8 Planck constant 	h 
1.054 571 628(53) × 10-34 J·s 	5.0 × 10-8 reduced Planck constant 	\hbar = h / (2 \pi) 

# Table of electromagnetic constants
# Quantity 	Symbol 	Value[5] (SI units) 	Relative Standard Uncertainty
1.256 637 061 × 10-6 N·A-2 	defined magnetic constant (vacuum permeability) 	?0  	4? × 10-7 N·A-2 = 
8.854 187 817 × 10-12 F·m-1 	defined electric constant (vacuum permittivity) 	\varepsilon_0 = 1/(\mu_0 c^2) \,  
376.730 313 461 ? 	defined characteristic impedance of vacuum 	Z0 = ?0c 
8.987 551 787 × 109 N·m²·C-2 	defined Coulomb's constant 	? = 1 / 4??0 
1.602 176 487(40) × 10-19 C 	2.5 × 10-8 elementary charge 	e 
927.400 915(23) × 10-26 J·T-1 	2.5 × 10-8 Bohr magneton 	\mu_B = e \hbar / 2 m_e 
7.748 091 7004(53) × 10-5 S 	6.8 × 10-10 conductance quantum 	G0 = 2e2 / h 
12 906.403 7787(88) ? 	6.8 × 10-10 inverse conductance quantum 	G0 - 1 = h / 2e2 
4.835 978 91(12) × 1014 Hz·V-1 	2.5 × 10-8 Josephson constant 	KJ = 2e / h 
2.067 833 667(52) × 10-15 Wb 	2.5 × 10-8 magnetic flux quantum 	?0 = h / 2e 
5.050 783 43(43) × 10-27 J·T-1 	8.6 × 10-8 nuclear magneton 	\mu_N = e \hbar / 2 m_p 
25 812.807 557(18) ? 	6.8 × 10-10 von Klitzing constant 	RK = h / e2 

# Table of atomic and nuclear constants
# Quantity 	Symbol 	Value[5] (SI units) 	Relative Standard Uncertainty
5.291 772 108(18) × 10-11 m 	3.3 × 10-9 Bohr radius 	a0 = ? / 4?R? 
2.817 940 2894(58) × 10-15 m 	2.1 × 10-9 classical electron radius 	re = e2 / 4??0mec2 
9.109 382 15(45) × 10-31 kg 	5.0 × 10-8 electron mass 	me 
1.166 39(1) × 10-5 GeV-2 	8.6 × 10-6 Fermi coupling constant 	G_F / (\hbar c)^3 
7.297 352 537 6(50) × 10-3 	6.8 × 10-10 fine-structure constant 	\alpha = \mu_0 e^2 c / (2 h) = e^2 / (4 \pi \epsilon_0 \hbar c) \, 
4.359 744 17(75) × 10-18 J 	1.7 × 10-7 Hartree energy 	Eh = 2R?hc 
1.672 621 637(83) × 10-27 kg 	5.0 × 10-8 proton mass 	mp 
3.636 947 550(24) × 10-4 m² s-1 	6.7 × 10-9 quantum of circulation 	h / 2me 
10 973 731.568 525(73) m-1 	6.6 × 10-12 Rydberg constant 	R? = ?2mec / 2h 
6.652 458 73(13) × 10-29 m² 	2.0 × 10-8 Thomson cross section 	(8? / 3)re2 
0.222 15(76) 	3.4 × 10-3 weak mixing angle 	sin2?W = 1 - (mW / mZ)2 

# Table of physico-chemical constants
# Quantity 	Symbol 	Value[5] (SI units) 	Relative Standard Uncertainty
1.660 538 86(28) × 10-27 kg 	1.7 × 10-7 atomic mass unit (unified atomic mass unit) 	mu = 1 u 
6.022 141 5(10) × 1023 mol-1 	1.7 × 10-7 Avogadro's number 	NA,L 
1.380 6504(24) × 10-23 J·K-1 	1.8 × 10-6 Boltzmann constant 	k = kB = R / NA 
96 485.3383(83)C·mol-1 	8.6 × 10-8 Faraday constant 	F = NAe 
3.741 771 18(19) × 10-16 W·m² 	5.0 × 10-8 first radiation constant 		c1 = 2?hc2 
1.191 042 82(20) × 10-16 W·m² sr-1 	1.7 × 10-7 for spectral radiance 	c1L 
2.686 777 3(47) × 1025 m-3 	1.8 × 10-6 Loschmidt constant 	at T=273.15 K and p=101.325 kPa 	n0 = NA / Vm 
8.314 472(15) J·K-1·mol-1 	1.7 × 10-6 gas constant 	R 
3.990 312 716(27) × 10-10 J·s·mol-1 	6.7 × 10-9 molar Planck constant 	NAh 
2.2710 981(40) × 10-2 m³·mol-1 	1.7 × 10-6 molar volume of an ideal gas 	at T=273.15 K and p=100 kPa 	Vm = RT / p 
2.2413 996(39) × 10-2 m³·mol-1 	1.7 × 10-6 at T=273.15 K and p=101.325 kPa 
 Sackur-Tetrode constant 	at T=1 K and p=100 kPa
-1.151 704 7(44) 	3.8 × 10-6 + \ln\left[ (2\pi m_u k T / h^2)^{3/2} k T / p \right] 
-1.164 867 7(44) 	3.8 × 10-6 at T=1 K and p=101.325 kPa 
1.438 775 2(25) × 10-2 m·K 	1.7 × 10-6 second radiation constant 	c2 = hc / k 
5.670 400(40) × 10-8 W·m-2·K-4 	7.0 × 10-6 Stefan Boltzmann constant 	\sigma = (\pi^2 / 60) k^4 / \hbar^3 c^2 
2.897 768 5(51) × 10-3 m·K 	1.7 × 10-6 Wien displacement law constant 	b = (hc / k) /   4.965 114 231... 

# Table of adopted values
# Quantity 	Symbol 	Value (SI units) 	Relative Standard Uncertainty
4.835 979 × 1014 Hz·V-1 	defined conventional value of Josephson constant[6] 	KJ - 90 
25 812.807 ? 	defined conventional value of von Klitzing constant[7] 	RK - 90 
 molar mass 	constant 	Mu = M( 12C) / 12 	1 × 10-3 kg·mol-1 	defined
 of carbon-12 	M( 12C) = NAm( 12C) 	1.2 × 10-2 kg·mol-1 	defined
9.806 65 m·s-2 	defined standard acceleration of gravity (gee, free-fall on Earth) 	g_n \,\! 
101 325 Pa 	defined standard atmosphere 	atm 
 
1.616 252(81) × 10-35 m Planck length 	Length (L) 	l_\text{P} = \sqrt{\frac{\hbar G}{c^3}} 
2.176 44(11) × 10-8 kg Planck mass 	Mass (M) 	m_\text{P} = \sqrt{\frac{\hbar c}{G}} 
5.391 24(27) × 10-44 s Planck time 	Time (T) 	t_\text{P} = \sqrt{\frac{\hbar G}{c^5}} 
1.875 545 870(47) × 10-18 C Planck charge 	Electric charge (Q) 	q_\text{P} = \sqrt{4 \pi \varepsilon_0 \hbar c} 
1.416 785(71) × 1032 K Planck temperature 	Temperature (?) 	T_\text{P} = \sqrt{\frac{\hbar c^5}{G k^2}} 
