| Quantity | Symbol | Value |
|---|---|---|
| Atomic mass unit | u | [latex] \begin{array}{c}1.660 538 782\,(83)\,×\,{10}^{-27}\,\text{kg}\hfill \\ 931.494 028\,(23)\,\text{MeV/}{c}^{2}\hfill \end{array} [/latex] |
| Avogadro’s number | [latex] {N}_{\text{A}} [/latex] | [latex] 6.022 141 79\,(30)\,×\,{10}^{23}\,\text{particles/mol} [/latex] |
| Bohr magneton | [latex] {\mu }_{\text{B}}=\frac{e\hslash }{2{m}_{e}} [/latex] | [latex] 9.274 009 15\,(23)\,×\,{10}^{-24}\,\text{J/T} [/latex] |
| Bohr radius | [latex] {a}_{0}=\frac{{\hslash }^{2}}{{m}_{e}{e}^{2}{k}_{e}} [/latex] | [latex] 5.291 772 085 9\,(36)\,×\,{10}^{-11}\,\text{m} [/latex] |
| Boltzmann’s constant | [latex] {k}_{\text{B}}=\frac{R}{{N}_{\text{A}}} [/latex] | [latex] 1.380 650 4\,(24)\,×\,{10}^{-23}\,\text{J/K} [/latex] |
| Compton wavelength | [latex] {\lambda }_{\text{C}}=\frac{h}{{m}_{e}c} [/latex] | [latex] 2.426 310 217 5\,(33)\,×\,{10}^{-12}\,\text{m} [/latex] |
| Coulomb constant | [latex] {k}_{e}=\frac{1}{4\pi {\text{ε}}_{0}} [/latex] | [latex] 8.987 551 788…\,×\,{10}^{9}\,\text{N}·{\text{m}}^{2}{\text{/C}}^{2}(\text{exact}) [/latex] |
| Deuteron mass | [latex] {m}_{d} [/latex] | [latex] \begin{array}{c}3.343 583 20\,(17)\,×\,{10}^{-27}\,\text{kg}\hfill \\ 2.013 553 212 724(78)\,\text{u}\hfill \\ 1875.612 859\,\text{MeV/}{c}^{2}\hfill \end{array} [/latex] |
| Electron mass | [latex] {m}_{e} [/latex] | [latex] \begin{array}{c}9.109 382 15\,(45)\,×\,{10}^{-31}\,\text{kg}\hfill \\ 5.485 799 094 3(23)\,×\,{10}^{-4}\,\text{u}\hfill \\ 0.510 998 910\,(13)\,\text{MeV/}{c}^{2}\hfill \end{array} [/latex] |
| Electron volt | eV | [latex] 1.602 176 487\,(40)\,×\,{10}^{-19}\,\text{J} [/latex] |
| Elementary charge | e | [latex] 1.602 176 487\,(40)\,×\,{10}^{-19}\,\text{C} [/latex] |
| Gas constant | R | [latex] 8.314 472\,(15)\,\text{J/mol}·\text{K} [/latex] |
| Gravitational constant | G | [latex] 6.674 28\,(67)\,×\,{10}^{-11}\,\text{N}·{\text{m}}^{2}{\text{/kg}}^{2} [/latex] |
| Neutron mass | [latex] {m}_{n} [/latex] | [latex] \begin{array}{c}1.674 927 211\,(84)\,×\,{10}^{-27}\,\text{kg}\hfill \\ 1.008 664 915 97\,(43)\,\text{u}\hfill \\ 939.565 346\,(23)\,\text{MeV/}{c}^{2}\hfill \end{array} [/latex] |
| Nuclear magneton | [latex] {\mu }_{n}=\frac{e\hslash }{2{m}_{p}} [/latex] | [latex] 5.050 783 24\,(13)\,×\,{10}^{-27}\,\text{J/T} [/latex] |
| Permeability of free space | [latex] {\mu }_{0} [/latex] | [latex] 4\pi \,×\,{10}^{-7}\,\text{T}·\text{m/A}(\text{exact}) [/latex] |
| Permittivity of free space | [latex] {\text{ε}}_{0}=\frac{1}{{\mu }_{0}{c}^{2}} [/latex] | [latex] 8.854 187 817…\,×\,{10}^{-12}\,{\text{C}}^{2}\text{/}\text{N}·{\text{m}}^{2}(\text{exact}) [/latex] |
| Planck’s constant | h
[latex] \hslash =\frac{h}{2\pi } [/latex] |
[latex] \begin{array}{c}6.626 068 96\,(33)\,×\,{10}^{-34}\,\text{J}·\text{s}\hfill \\ 1.054 571 628\,(53)\,×\,{10}^{-34}\,\text{J}·\text{s}\hfill \end{array} [/latex] |
| Proton mass | [latex] {m}_{p} [/latex] | [latex] \begin{array}{c}1.672 621 637\,(83)\,×\,{10}^{-27}\,\text{kg}\hfill \\ 1.007 276 466 77\,(10)\,\text{u}\hfill \\ 938.272 013\,(23)\,\text{MeV/}{c}^{2}\hfill \end{array} [/latex] |
| Rydberg constant | [latex] {R}_{\text{H}} [/latex] | [latex] 1.097 373 156 852 7\,(73)\,×\,{10}^{7}\,{\text{m}}^{-1} [/latex] |
| Speed of light in vacuum | c | [latex] 2.997 924 58\,×\,{10}^{8}\,\text{m/s}\,(\text{exact}) [/latex] |
Useful combinations of constants for calculations:
[latex] hc=12,400\,\text{eV}·\text{Å}=1240\,\text{eV}·\text{nm}=1240\,\text{MeV}·\text{fm} [/latex]
[latex] \hslash c=1973\,\text{eV}·\text{Å}=197.3\,\text{eV}·\text{nm}=197.3\,\text{MeV}·\text{fm} [/latex]
[latex] {k}_{e}{e}^{2}=14.40\,\text{eV}·\text{Å}=1.440\,\text{eV}·\text{nm}=1.440\,\text{MeV}·\text{fm} [/latex]
[latex] {k}_{\text{B}}T=0.02585\,\text{eV at}\,T=300\,\text{K} [/latex]
