Recommended Values of Physical Constants and Conversion Factors
Please read the notes following the table.
| Quantity | Value |
|---|
| speed of light in a vacuum (c) | 2.99792458E+08 m/s (exact) |
| permeability of a vacuum (µ0) | 4π×1.0E-07 H/m |
| permittivity of a vacuum (ε0) | 8.854187817...E-12 F/m |
| elementary charge (of proton) | 1.60217733(49)E-19 C |
| gravitational constant | 6.67259(85)E-11 Nm2kg-2 |
| unified atomic mass constant (mu = mass 12C / 12) | 1.6605402(10)E-27 kg |
| rest mass of electron (me) | 9.1093897(54)E-31 kg |
| 5.48579903(13)E-04 amu |
| rest mass of proton (mp) | 1.6726231(10)E-27 kg |
| 1.007276470(12) amu |
| 1836.152701(37) me |
| rest mass of neutron (mn) | 1.6749286(10)E-27 kg |
| 1.008664904(14) amu |
| energy equivalence of rest mass of electron | 0.5109906(15) MeV |
| energy equivalence of rest mass of proton | 938.27231(28) MeV |
| energy equivalence of rest mass of neutron | 939.56563(28) MeV |
|
| electron specific charge (-e/me) | -1.75881962(53)E11 C/kg |
| Planck constant | 6.6260755(40)E-34 Js |
| h/2π | 1.05457266(63)E-34 Js |
| Rydberg constant | 1.0973731534E+07 1/m |
| fine structure constant | 7.29735308(33)E-03 |
| reciprocal fine structure constant | 137.0359895(61) |
| Hartree energy | 4.3597482(26)E-18 J |
| 2.6255000E+06 J/mol |
| 27.211652 eV |
| 627.51E+03 Calories/mol (US Calorie) |
| Bohr radius | 5.29177249(24)E-11 m |
| electron radius | 2.81794092(38)E-15 m |
| Compton wavelength of electron | 2.42631058(22)E-12 m |
| Compton wavelength of proton | 1.32141002(12)E-15 m |
| Compton wavelength of neutron | 1.31959110(12)E-15 m |
|
| Avogadro constant (NA, L) | 6.0221367(36)E+23 1/mol |
| Faraday constant | 9.6485309(29)E+04 C/mol |
| molar gas constant | 8.314510(70) J/K/mol |
| Boltzman constant | 1.380658(12)E-23 J/K |
| Stefan-Boltzman constant | 5.67051(19)E-08 W/m2K-4 |
| first radiation constant | 3.7417749(22)E-16 Jm2s-1 |
| second radiation constant | 1.438769(12)E-02 mK |
| Bohr magneton | 9.2740154(31)E-24 J/T |
| nuclear magneton | 5.0507866(17)E-27 J/T |
| magnetic flux quantum | 2.06783461(61)E-15 Vs |
|
| gyromagnetic ratio of proton | 2.67522128(81)E+08 1/s/T |
| *1/2π | 4.2577469(13)E+07 Hz/T |
| in pure water | 2.67515255(81)E+08 1/s/T |
| *1/2π | 4.2756375(13)E+07 Hz/T |
|
| magnetic moment of electron | 9.2847701(31)E-24 J/T |
| in terms of Bohr magneton | 1.001159652(10) |
|
| magnetic moment of proton | 1.41060761(47)E-26 J/T |
| in terms of Bohr magneton | 1.521032202(15)E+03 |
| in pure water | 1.520993129(17)E+03 |
| in terms of nuclear magneton | 2.792847386(63) |
|
| Electronvolts per mol | 96.485333E+03 J/mol |
| 23.060548E+03 Calories/mol |
| 1/cm (harmonic oscillator) | 9.93223731E-24 J |
| 5.98132908 J/mol |
| 8.06554093 E-3 eV |
| Calorie (USA - definition) | 4.18400 J |
| Mean Calorie | 4.19002 J |
| 15 deg C Calorie | 4.1890 J |
| 220 lattice parameter of silicon (d220 = a/80.5) | 1.92015540(40)E-13 |
Notes
The above values are taken from Refs. [1-3]: these are good enough for most purposes. Recently new values have been published which are considerably more accurate, except for the gravitational constant, G. For details of these please see Ref. [4] and the NIST website.
References
- E. R. Cohen and B. N. Taylor, "The 1986 CODATA recommended values of the fundamental physical constants.", J. Res. National Bureau of Standards, 92(2), 85-95 (1987).
- E. R. Cohen and B. N. Taylor, "The 1986 adjustment of the fundamental physical constants", CODATA Bulletin Number 63, (1986); and Rev. Mod. Phys., 59(4), 1121-1148 (1987).
- CRC Handbook of Chemistry and Physics, 58th edition (1977-78).
- P. J. Mohr and B. N. Taylor, "CODATA recommended values of the fundamental physical constants: 1998", J. Phys. Chem. Ref. Data, 28(6) (1999); and Rev. Mod. Phys., 72(2), 1713-1852, (2000).
The number in parenthesis after each value is the estimated standard deviation uncertainty of the last digit quoted.
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Last modified: Tue Nov 18 16:00:08 GMT 2003
Chris Latham, Chris Ewels.
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