Physical Constants
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Physical Constants | Unit |
---|---|
Atomic mass unit (u) | 1 u = 1.66053906660 × 10−24 g |
1 g = 6.0221407621 × 1023 u | |
Avogadro’s number (NA) | 6.022142 × 1023/mol |
Boltzmann’s constant (k) | 1.380651 × 10−23 J/K |
Charge on electron (e) | 1.60217634 × 10−19 C |
Faraday’s constant (F) | 9.6485338 × 104 C/mol |
Gas constant (R) | R=k NA |
0.0820575 (L atm)/(mol K) = 8.31447 J/(mol K) |
|
Mass of electron (mn) | 5.485799 × 10−4 amu |
= 9.109383 × 10−28 g | |
Mass of neutron (mn) | 1.0086649 u |
= 1.6749273 × 10−24 g | |
Mass of proton (mp) | 1.0072765 u |
= 1.6726217 × 10−24 g | |
Pi | π = 3.1415927 |
Planck’s constant (h) |
h = 6.626069 × 10 −34J s ℏ=h2π=1.05457266·10-34 J·s |
Speed of light in vacuum (c) | c = 2.99792458 × 108 m/s (exact) |
Permeability of vacuum μ0 |
μ0=4π ·10-7 T2·m3/J 12.566370614·10-7 T2·m3/J |
Permittivity of vacuum ϵ0 |
ϵ0=1μoc2 8.854187817·10-12 C2/J·m |
Fine structure constant α | 1137.0359895 |
Bohr magneton μB |
μB=eh4πme 9.2740154·10-24 J/T |
Nuclear magneton μN |
μN=eh4πmp 5.0507866·10-27 J/T |
Free electron g factor ge |
2.002319304386 |
Free electron gyromagnetic ratio γe |
γe=2geBh 1.7608592·1011 1/s·T γe2π = 28.024944 GHz/T |
Electron magnetic moment μe |
μe=−geμB2 -9.2847701·10-24 J/T |
Proton gyromagnetic ratio (H2O) γp |
2.67515255·108 1/s·T γp2π = 42.576375 MHz/T |
Proton magnetic momentμp |
1.41060761·10-26 J/T |
Charge-to-mass ratio for the electron eme |
1.75880·1011 C/kg |
Bohr radius a0 |
5.29177·10-11 m |
Electron radius re |
2.81792·10-15 m |
Proton g factor (Landé factor) gH | 5.585 |
Gravitational constant G |
(6.673 ± 0.010)·10-11 m3/kg·s2 (CODATA) |
Acceleration due to gravity g |
9.80665 m/s2 |
Compton wavelength of the electron λc | 2.42631·10-12 m |
Atomic energy unit Hartree |
1 Hartree = e24πϵoa0 1 Hartree = 2.625501·106 J/mol (approx. 627.5 kcal/mol) |
Proton Larmor frequency |
νp=γp/2πB νp = 42.5764 MHz/T (H2O) |
Electron Larmor frequency |
νe = νe2π (g / ge) B νe [GHz] = 13.9962 g B [T] g = 0.07144775 νe [GHz] / B [T] g = 3.04199νe [GHz] / νp [MHz] B [T] = 0.0234872 νp [MHz] |
Conversion of Units |
1 G = 0.1 mT 1 T = 10 kG 1 mT = 10 G A [MHz] = 2.80249 (g / ge) A [G] A [MHz] = 28.0249 (g / ge) A [mT] A [MHz] = 13.9962 g A [mT] A [MHz] = 2.99792·104 A [cm-1] A [cm-1] = 0.333564·10-4 A [MHz] A [cm-1] = 4.66863·10-4 g A [mT] |
(Note that the use of brackets [ ] in the following expressions is not in accordance with standards which require the use of a slash, e.g. A/MHz.)