Fundamental Physical Constants

 

Certain physical constants have special importance on account of their universality or place in fundamental theory. These constants are given below in SI units. The figure in brackets is the estimated uncertainty in the last digit.

 

Table 1: Physical Constants - General Constants
Quantity	Symbol	Value	Unit
Speed of light in vacuum	c	2.997924590(8) * 108	m.s-1
Planck constant	h	6.62620(5) * 10-34	J.Hz-1
Electron charge	e	1.602192(7) * 10-19	C
Gas constant	R	8.31	J.K-1.mol-1
Gravitational constant	GN	6.673 * 10-11	m3 kg-1 s-2
Standard grav. accel., sea level	gn	9.806 * 105	kg

 

 

Table 2: Physical Constants - Electron Constants
Quantity	Symbol	Value	Unit
Electron rest mass	me	9.10956(5) x 10-31	kg
Electron rest energy	mec2	8.18726(6) x 10-14	J
Electron charge-mass ratio	e/me	1.758803(5) x 1011	C.kg-1
Radius of electron	re	2.817939(13) x 10-15	m

 

 

Table 3: Physical Constants - Proton Constants
Quantity	Symbol	Value	Unit
Proton rest mass	mp	1.672614(11) x 10-27	kg
Proton rest energy	mpc2	1.503271(15) x 10-10	J
Proton charge-mass ratio	e/mp	9.57897(11) x 107	C.kg-1

 

 

Table 4: Physical Constants - Neutron Constants
Quantity	Symbol	Value	Unit
Neutron rest mass	mn	1.674920(11) x 10-27	kg
Neutron rest energy	mnc2	1.505343(15) x 10-10	J

 

 

Table 5: Physical Constants - Atomic Constants
Quantity	Symbol	Value	Unit
Rydberg constant	R	1.0973731(1) * 107	m-1
Bohr radius	ao	5.291772(8) * 10-11	m
Bohr magneton	µ	9.27410(6) * 10-24	J.T-1
Nuclear magneton	µn	5.05095(5) * 10-27	J.T-1
Zeeman splitting constant	µ/hc	4.66860(7) * 101	m-1T-1

 

 

Table 6: Physical Constants - Matter Constants
Quantity	Symbol	Value	Unit
Avogadro constant	N	6.02217(4) * 1023	mol-1
Faraday	F	9.64867(5) * 104	Cmol-1
Normal volume of ideal gas	Vo	2.24136(30) * 10-2	m3.mol-1
Gas constant	R	8.3143(3) * 100	J.K-1mol-1
Boltzmann constant	k	1.38062(6) * 10-23	J.K-1

 

 

Table 7: Units of Gas Constant (R)
Quantity	Symbol	Value	Unit
Gas contant	R	8.3143(3)	J.K-1mol-1
R = 8.3143(3) J.K-1.mol-1 = 1.98 cal/deg.mol = 82.05 cm3 atm deg-1 mol-1

 

 

Table 8: Units of Pressure
Quantity	Symbol	Value	Unit
Pressure	P	1 N.m-2 = 1 Pa	Pa = N.m-2
Pressure is measured in N.m-2 = 1 Pa 1 atm = 760 mmHg = 101325 kPa

 

 

Table 9: SI Prefixes
Name	Symbol	Value
pico	p	10-12
nano	n	10-9
micro	µ	10-6
milli	m	10-3
centi	c	10-2
deci	d	10-1
kilo	k	103
mega	M	106
giga	G	109

tera	T	1012

 

 

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Relevant Posts

Useful Conversion Factors between Units of Fundamental Physical Constants

 

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References

1. P.J. Mohr and B.N. Taylor, J. Phys. Chem. Ref. Data, 28, 1713 (1999)
2.  P.J. Mohr and B.N. Taylor, Rev. Mod. Phys., 72, 351 (2000)
3. Physical Constants
4. R.M. Tennent, "Science Data Book", Oliver & Boyd, (1979)

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Key Terms

fundamental physical constants, chemical data, physical data, thermochemical data

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