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66.25: Fundamental Physical Constants — Extensive Listing

  • Page ID
    91955
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    Table \(\PageIndex{1}\): Universal Fundamental Constants

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    speed of light in vacuum \(c\)

    \(299\; 792\; 458\)

    \(\mathrm{~m} \mathrm{~s}^{-1}\) exact
    vacuum magnetic permeability \(4 \pi \alpha \hbar / e^2 c\) \(\mu_0\) \(1.25663706212(19) \times 10^{-6}\) \(\mathrm{NA}^{-2}\) \(1.5 \times 10^{-10}\)
    \(\mu_0 /\left(4 \pi \times 10^{-7}\right)\) \(1.00000000055(15)\) \(\mathrm{NA}^{-2}\) \(1.5 \times 10^{-10}\)
    vacuum electric permittivity \(1 / \mu_0 c^2\) \(\epsilon_0\) \(8.8541878128(13) \times 10^{-12}\) \(\mathrm{~F} \mathrm{~m}^{-1}\) \(1.5 \times 10^{-10}\)
    characteristic impedance of vacuum \(\mu_0 c\) \(Z_0\) \(376.730313668(57)\) \(\Omega\) \(1.5 \times 10^{-10}\)
    Newtonian constant of gravitation \(G\) \(6.67430(15) \times 10^{-11}\) \(\mathrm{~m}^3 \mathrm{~kg}^{-1} \mathrm{~s}^{-2}\) \(2.2 \times 10^{-5}\)
      \(G / \hbar c\) \(6.70883(15) \times 10^{-39}\) \(\left(\mathrm{GeV} / c^2\right)^{-2}\) \(2.2 \times 10^{-5}\)
    Planck constant* \(h\) \(6.62607015 \times 10^{-34}\) \(\mathrm{~J} \mathrm{~Hz}^{-1}\) exact
        \(4.135667696 \ldots \times 10^{-15}\) \(\mathrm{eV} \mathrm{Hz}^{-1}\) exact
      \(\hbar\) \(1.054571817 \ldots \times 10^{-34}\) \(J s\) exact
        \(6.582119569 \ldots \times 10^{-16}\) \(\mathrm{eV} \mathrm{s}\) exact
      \(\hbar c\) \(197.3269804 \ldots\) \(\mathrm{MeV} \mathrm{fm}\) exact
    Planck mass (\(\hbar c / G)^{1 / 2}\) \(m_{\mathrm{P}}\) \(2.176434(24) \times 10^{-8}\) \(\mathrm{~kg}\) \(1.1 \times 10^{-5}\)
    energy equivalent \(m_{\mathrm{P}} c^2\) \(1.220890(14) \times 10^{19}\) \(\mathrm{GeV}\) \(1.1 \times 10^{-5}\)
    Planck temperature \(\left(\hbar c^5 / G\right)^{1 / 2} / k\) \(T_{\mathrm{P}}\) \(1.416784(16) \times 10^{32}\) \(K\) \(1.1 \times 10^{-5}\)
    Planck length \(\hbar / m_{\mathrm{P}} c=\left(\hbar G / c^3\right)^{1 / 2}\) \(l_{\mathrm{P}}\) \(1.616255(18) \times 10^{-35}\) \(\mathrm{~m}\) \(1.1 \times 10^{-5}\)
    Planck time \(l_{\mathrm{P}} / c=\left(\hbar G / c^5\right)^{1 / 2}\) \(t_{\mathrm{P}}\) \(5.391247(60) \times 10^{-44}\) \(s\) \(1.1 \times 10^{-5}\)

    Table \(\PageIndex{2}\): Electromagnetic Constants

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    elementary charge \(e\) \(1.602176634 \times 10^{-19}\) \(\mathrm{C}\) exact
             
      \(e / \hbar\) \(1.519267447 \ldots \times 10^{15}\) \(\mathrm{~A} \mathrm{~J}^{-1}\) exact
    magnetic flux quantum \(2 \pi \hbar /(2 e)\) \(\Phi_0\) \(2.067833848 \ldots \times 10^{-15}\) \(\mathrm{~Wb}\) exact
    conductance quantum \(2 e^2 / 2 \pi \hbar\) \(G_0\) \(7.748091729 \ldots \times 10^{-5}\) \(\mathrm{~S}\) exact
    \(\quad\) inverse of conductance quantum \(G_0^{-1}\) \(12906.40372 \ldots\) \(\Omega\) exact
    Josephson constant \(2 e / h\) \(K_{\mathrm{J}}\) \(483597.8484 \ldots \times 10^9\) \(\mathrm{~Hz} \mathrm{~V}^{-1}\) exact
    von Klitzing constant \(\mu_0 c / 2 \alpha=2 \pi \hbar / e^2\) \(R_{\mathrm{K}}\) \(25812.80745 \ldots\) \(\Omega\) exact
    Bohr magneton \(e \hbar / 2 m_{\mathrm{e}}\) \(\mu_{\mathrm{B}}\) \(9.2740100783(28) \times 10^{-24}\) \(\mathrm{~J} \mathrm{~T}^{-1}\) \(3.0 \times 10^{-10}\)
        \(5.7883818060(17) \times 10^{-5}\) \(\mathrm{eV} \mathrm{T}^{-1}\) \(3.0 \times 10^{-10}\)
      \(\mu_{\mathrm{B}} / h\) \(1.39962449361(42) \times 10^{10}\) \(\mathrm{~Hz} \mathrm{~T}^{-1}\) \(3.0 \times 10^{-10}\)
      \(\mu_{\mathrm{B}} / h c\) \(46.686447783(14)\) \(\left[\mathrm{m}^{-1} \mathrm{~T}^{-1}\right]^{\dagger}\) \(3.0 \times 10^{-10}\)
      \(\mu_{\mathrm{B}} / k\) \(0.67171381563(20)\) \(\mathrm{K} \mathrm{T}^{-1}\) \(3.0 \times 10^{-10}\)
    nuclear magneton \(e \hbar / 2 m_{\mathrm{p}}\) \(\mu_{\mathrm{N}}\) \(5.0507837461(15) \times 10^{-27}\) \(\mathrm{~J} \mathrm{~T}^{-1}\) \(3.1 \times 10^{-10}\)
        \(3.15245125844(96) \times 10^{-8}\) \(\mathrm{eV} \mathrm{T}^{-1}\) \(3.1 \times 10^{-10}\)
      \(\mu_{\mathrm{N}} / h\) \(7.6225932291(23)\) \(\mathrm{MHz} \mathrm{T}^{-1}\) \(3.1 \times 10^{-10}\)
      \(\mu_{\mathrm{N}} / h c\) \(2.54262341353(78) \times 10^{-2}\) \(\left[\mathrm{~m}^{-1} \mathrm{~T}^{-1}\right]^{\dagger}\) \(3.1 \times 10^{-10}\)
      \(\mu_{\mathrm{N}} / k\) \(3.6582677756(11) \times 10^{-4}\) \(\mathrm{~K} \mathrm{~T}^{-1}\) \(3.1 \times 10^{-10}\)

    Table \(\PageIndex{3}\): General Atomic and Nuclear Constants

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    fine-structure constant \(e^2 / 4 \pi \epsilon_0 \hbar c\) \(\alpha\) \(7.2973525693(11) \times 10^{-3}\) \(1.5 \times 10^{-10}\)
    \(\quad\) inverse fine-structure constant \(\alpha^{-1}\) \(137.035999084(21)\) \(1.5 \times 10^{-10}\)
    Rydberg frequency \(\alpha^2 m_{\mathrm{e}} c^2 / 2 h=E_{\mathrm{h}} / 2 h\) \(c R_{\infty}\) \(3.2898419602508(64) \times 10^{15}\) \(\mathrm{~Hz}\) \(1.9 \times 10^{-12}\)
    \(\quad\) energy equivalent \(h c R_{\infty}\) \(2.1798723611035(42) \times 10^{-18}\) \(\mathrm{~J}\) \(1.9 \times 10^{-12}\)
        \(13.605693122994(26)\) \(\mathrm{eV}\) \(1.9 \times 10^{-12}\)
    Rydberg constant \(R_{\infty}\) \(10973731.568160(21)\) \(\left[\mathrm{m}^{-1}\right]^{\dagger}\) \(1.9 \times 10^{-12}\)
    Bohr radius \(\hbar / \alpha m_{\mathrm{e}} c=4 \pi \epsilon_0 \hbar^2 / m_{\mathrm{e}} e^2\) \(a_0\) \(5.29177210903(80) \times 10^{-11}\) \(\mathrm{~m}\) \(1.5 \times 10^{-10}\)
    Hartree energy \(\alpha^2 m_{\mathrm{e}} c^2=e^2 / 4 \pi \epsilon_0 a_0=2 h c R_{\infty}\) \(E_{\mathrm{h}}\) \(4.3597447222071(85) \times 10^{-18}\) \(\mathrm{~J}\) \(1.9 \times 10^{-12}\)
        \(27.211386245988(53)\) \(\mathrm{eV}\) \(1.9 \times 10^{-12}\)
    quantum of circulation \(\pi \hbar / m_{\mathrm{e}}\) \(3.6369475516(11) \times 10^{-4}\) \(\mathrm{~m}^2 \mathrm{~s}^{-1}\) \(3.0 \times 10^{-10}\)
      \(2 \pi \hbar / m_{\mathrm{e}}\) \(7.2738951032(22) \times 10^{-4}\) \(\mathrm{~m}^2 \mathrm{~s}^{-1}\) \(3.0 \times 10^{-10}\)

    Table \(\PageIndex{4}\): Electroweak Constants

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    Fermi coupling constant \({ }^{\ddagger}\) \(G_{\mathrm{F}} /(\hbar c)^3\) \(1.1663787(6) \times 10^{-5}\) \(\mathrm{GeV}^{-2}\) \(5.1 \times 10^{-7}\)
    \(\sin ^2 \theta_{\mathrm{W}}=s_{\mathrm{W}}^2 \equiv 1-\left(m_{\mathrm{W}} / m_{\mathrm{Z}}\right)^2\) \(\sin ^2 \theta_{\mathrm{W}}\) \(0.22290(30)\) \(1.3 \times 10^{-3}\)
    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    electron mass \(m_{\mathrm{e}}\) \(9.1093837015(28) \times 10^{-31}\) \(\mathrm{kg}\) \(3.0 \times 10^{-10}\)
        \(5.48579909065(16) \times 10^{-4}\) \(\mathrm{u}\) \(2.9 \times 10^{-11}\)
    energy equivalent \(m_{\mathrm{e}} c^2\) \(8.1871057769(25) \times 10^{-14}\) \(J\) \(3.0 \times 10^{-10}\)
        \(0.51099895000(15)\) \(\mathrm{MeV}\) \(3.0 \times 10^{-10}\)
    electron-muon mass ratio \(m_{\mathrm{e}} / m_\mu\) \(4.83633169(11) \times 10^{-3}\) \(2.2 \times 10^{-8}\)
    electron-tau mass ratio \(m_{\mathrm{e}} / m_\tau\) \(2.87585(19) \times 10^{-4}\) \(6.8 \times 10^{-5}\)
    electron-proton mass ratio \(m_{\mathrm{e}} / m_{\mathrm{p}}\) \(5.44617021487(33) \times 10^{-4}\) \(6.0 \times 10^{-11}\)
    electron-neutron mass ratio \(m_{\mathrm{e}} / m_{\mathrm{n}}\) \(5.4386734424(26) \times 10^{-4}\) \(4.8 \times 10^{-10}\)
    electron-deuteron mass ratio \(m_{\mathrm{e}} / m_{\mathrm{d}}\) \(2.724437107462(96) \times 10^{-4}\) \(3.5 \times 10^{-11}\)
    electron-triton mass ratio \(m_{\mathrm{e}} / m_{\mathrm{t}}\) \(1.819200062251(90) \times 10^{-4}\) \(5.0 \times 10^{-11}\)
    electron-helion mass ratio \(m_{\mathrm{e}} / m_{\mathrm{h}}\) \(1.819543074573(79) \times 10^{-4}\) \(4.3 \times 10^{-11}\)
    electron to alpha particle mass ratio \(m_{\mathrm{e}} / m_\alpha\) \(1.370933554787(45) \times 10^{-4}\) \(3.3 \times 10^{-11}\)
    electron charge to mass quotient \(-e / m_{\mathrm{e}}\) \(-1.75882001076(53) \times 10^{11}\) \(\mathrm{C} \mathrm{kg}^{-1}\) \(3.0 \times 10^{-10}\)
    electron molar mass \(N_{\mathrm{A}} m_{\mathrm{e}}\) \(M(\mathrm{e}), M_{\mathrm{e}}\) \(5.4857990888(17) \times 10^{-7}\) \(\mathrm{~kg} \mathrm{~mol}^{-1}\) \(3.0 \times 10^{-10}\)
    reduced Compton wavelength \( \hbar / m_{\mathrm{e}} c=\alpha a_0\) \(\lambda_{\mathrm{C}}\) \(3.8615926796(12) \times 10^{-13}\) \(\mathrm{~m}\) \(3.0 \times 10^{-10}\)
    Compton wavelength \(\lambda_{\mathrm{C}}\) \(2.42631023867(73) \times 10^{-12}\) \([\mathrm{~m}]^{\dagger}\) \(3.0 \times 10^{-10}\)
    classical electron radius \(\alpha^2 a_0\) \(r_{\mathrm{e}}\) \(2.8179403262(13) \times 10^{-15}\) \(\mathrm{~m}\) \(4.5 \times 10^{-10}\)
    Thomson cross section \((8 \pi / 3) r_{\mathrm{e}}^2\) \(\sigma_{\mathrm{e}}\) \(6.6524587321(60) \times 10^{-29}\) \(\mathrm{~m}^2\) \(9.1 \times 10^{-10}\)
    electron magnetic moment \(\mu_{\mathrm{e}}\) \(-9.2847647043(28) \times 10^{-24}\) \(\mathrm{~J} \mathrm{~T}^{-1}\) \(3.0 \times 10^{-10}\)
    to Bohr magneton ratio \(\mu_{\mathrm{e}} / \mu_{\mathrm{B}}\) \(-1.00115965218128(18)\) \(1.7 \times 10^{-13}\)
    to nuclear magneton ratio \(\mu_{\mathrm{e}} / \mu_{\mathrm{N}}\) \(-1838.28197188(11)\) \(6.0 \times 10^{-11}\)
    electron magnetic moment        
    anomaly \(\left|\mu_{\mathrm{e}}\right| / \mu_{\mathrm{B}}-1\) \(a_{\mathrm{e}}\) \(1.15965218128(18) \times 10^{-3}\) \(1.5 \times 10^{-10}\)
    electron g-factor \((-2\left(1+a_{\mathrm{e}}\right)\)) \(g_{\mathrm{e}}\) \(-2.00231930436256(35)\) \(1.7 \times 10^{-13}\)
    electron-muon magnetic moment ratio \(\mu_{\mathrm{e}} / \mu_\mu\) \(206.7669883(46)\) \(2.2 \times 10^{-8}\)
    electron-proton magnetic moment ratio
    electron to shielded proton magnetic
    \(\mu_{\mathrm{e}} / \mu_{\mathrm{p}}\) \(-658.21068789(20)\) \(3.0 \times 10^{-10}\)
    moment ratio \(\left(\mathrm{H}_2 \mathrm{O}\right., sphere, \left.25^{\circ} \mathrm{C}\right)\) \(\mu_{\mathrm{e}} / \mu_{\mathrm{p}}^{\prime}\) \(-658.2275971(72)\)\) \(1.1 \times 10^{-8}\)
    electron-neutron magnetic moment ratio \(\mu_{\mathrm{e}} / \mu_{\mathrm{n}}\) \(960.92050(23)\) \(2.4 \times 10^{-7}\)
    electron-deuteron magnetic moment ratio
    electron to shielded helion magnetic
    \(\mu_{\mathrm{e}} / \mu_{\mathrm{d}}\) \(-2143.9234915(56)\) \(2.6 \times 10^{-9}\)
    moment ratio (gas, sphere, \(25^{\circ} \mathrm{C}\) ) \(\mu_{\mathrm{e}} / \mu_{\mathrm{h}}^{\prime}\) \(864.058257(10)\) \(1.2 \times 10^{-8}\)
    electron gyromagnetic ratio \(2\left|\mu_{\mathrm{e}}\right| / \hbar\) \(\gamma_{\mathrm{e}}\) \(1.76085963023(53) \times 10^{11}\) \(\mathrm{~s}^{-1} \mathrm{~T}^{-1}\) \(3.0 \times 10^{-10}\)
        \(28024.9514242(85)\) \(\mathrm{MHz}\mathrm{T}^{-1}\) \(3.0 \times 10^{-10}\)

    Table \(\PageIndex{6}\): Muon, \(mu_{-}\)

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    muon mass \(m_\mu\) \(1.883531627(42) \times 10^{-28}\) \(\mathrm{~kg}\) \(2.2 \times 10^{-8}\)
        \(0.1134289259(25)\) \(\mathrm{u}\) \(2.2 \times 10^{-8}\)
    energy equivalent   \(1.692833804(38) \times 10^{-11}\) \(\mathrm{~J}\) \(2.2 \times 10^{-8}\)
      \(m_\mu c^2\) \(105.6583755(23)\) \(\mathrm{MeV}\) \(2.2 \times 10^{-8}\)
    muon-electron mass ratio \(m_\mu / m_{\mathrm{e}}\) \(206.7682830(46)\)   \(2.2 \times 10^{-8}\)
    muon-tau mass ratio \(m_\mu / m_\tau\) \(5.94635(40) \times 10^{-2}\)   \(6.8 \times 10^{-5}\)
    muon-proton mass ratio \(m_\mu / m_{p}\) \(0.112 609 5264(25)\)   \(2.2 \times 10^{-8}\)
    muon-neutron mass ratio \(m_\mu / m_{\mathrm{n}}\) \(0.1124545170(25)\)   \(2.2 \times 10^{-8}\)
    muon molar mass \(N_{\mathrm{A}} m_\mu\) \(M(\mu), M_\mu\) \(1.134289259(25) \times 10^{-4}\) \(\mathrm{~kg} \mathrm{~mol}^{-1}\) \(2.2 \times 10^{-8}\)
    reduced muon Compton wavelength \(\hbar / m_\mu c\) \(\lambda_{\mathrm{C}, \mu}\) \(1.867594306(42) \times 10^{-15}\) \(\mathrm{~m}\) \(2.2 \times 10^{-8}\)
    \(\quad\) muon Compton wavelength \(\lambda_{\mathrm{C}, \mu}\) \(1.173444110(26) \times 10^{-14}\) \([\mathrm{~m}]^{\dagger}\) \(2.2 \times 10^{-8}\)
    muon magnetic moment \(\mu_\mu\) \(-4.49044830(10) \times 10^{-26}\) \(\mathrm{~J} \mathrm{~T}^{-1}\) \(2.2 \times 10^{-8}\)
    \(\quad\) to Bohr magneton ratio \(\mu_\mu / \mu_{\mathrm{B}}\) \(-4.84197047(11) \times 10^{-3}\)   \(2.2 \times 10^{-8}\)
    \(\quad\) to nuclear magneton ratio \(\mu_\mu / \mu_{\mathrm{N}}\) \(-8.89059703(20)\)   \(2.2 \times 10^{-8}\)
    muon magnetic moment anomaly       \(5.4 \times 10^{-7}\)
    \(\left|\mu_\mu\right| /\left(e \hbar / 2 m_\mu\right)-1\) \(a_\mu\) \(1.16592089(63) \times 10^{-3}\) \(6.3 \times 10^{-10}\)
    muon g-factor \(-2\left(1+a_\mu\right)\) \(g_\mu\) \(-2.0023318418(13)\) \(2.2 \times 10^{-8}\)
    muon-proton magnetic moment ratio \(\mu_\mu / \mu_{\mathrm{p}}\) \(-3.183345142(71)\)  

    Table \(\PageIndex{7}\): Tau, \(tau_{-}\)

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    tau mass \(m_\tau\) \(3.16754(21) \times 10^{-27}\) \(\mathrm{~kg}\) \(6.8 \times 10^{-5}\)
        \(1.90754(13)\) \(\mathrm{u}\) \(6.8 \times 10^{-5}\)
    energy equivalent \(m_\tau c^2\) \(2.84684(19) \times 10^{-10}\) \(\mathrm{~J}\) \(6.8 \times 10^{-5}\)
        \(1776.86(12)\) \(\mathrm{MeV}\) \(6.8 \times 10^{-5}\)
    tau-electron mass ratio \(m_\tau / m_{\mathrm{e}}\) \(3477.23(23)\)   \(6.8 \times 10^{-5}\)
    tau-muon mass ratio \(m_\tau / m_\mu\) \(16.8170(11)\)   \(6.8 \times 10^{-5}\)
    tau-proton mass ratio \(m_\tau / m_{\mathrm{p}}\) \(1.89376(13)\)   \(6.8 \times 10^{-5}\)
    tau-neutron mass ratio \(m_\tau / m_{\mathrm{n}}\) \(1.89115(13)\)   \(6.8 \times 10^{-5}\)
    tau molar mass \(N_{\mathrm{A}} m_\tau \) \(M_{\mathrm{C}, \tau}\) \(1.90754(13) \times 10^{-3}\) \(\mathrm{~kg} \mathrm{~mol}^{-1}\) \(6.8 \times 10^{-5}\)
    reduced tau Compton wavelength \(\hbar / m_\tau c \) \(\lambda_{\mathrm{C}, \tau}\) \(1.110538(75) \times 10^{-16}\) \([\mathrm{~m}]^{\dagger}\) \(6.8 \times 10^{-5}\)
    tau Compton wavelength \(\lambda_{\mathrm{C}, \tau}\) \(6.97771(47) \times 10^{-16}\) \([m]\) \(6.8 \times 10^{-5}\)

    Table \(\PageIndex{8}\): Proton, p

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    proton-tau mass ratio \(m_{\mathrm{p}} / m_\tau\) \(0.528051(36)\)   \(6.8 \times 10^{-5}\)
    proton-neutron mass ratio \(m_{\mathrm{p}} / m_{\mathrm{n}}\) \(0.99862347812(49)\)   \(4.9 \times 10^{-10}\)
    proton charge to mass quotient \(e / m_{\mathrm{p}}\) \(9.5788331560(29) \times 10^7\) \(\mathrm{C} \mathrm{kg}^{-1}\) \(3.1 \times 10^{-10}\)
    proton molar mass \(N_{\mathrm{A}} m_{\mathrm{p}}\) \(M(\mathrm{p}), M_{\mathrm{p}}\) \(1.00727646627(31) \times 10^{-3}\) \(\mathrm{~kg} \mathrm{~mol}^{-1}\) \(3.1 \times 10^{-10}\)
    reduced proton Compton wavelength \(\hbar / m_{\mathrm{p}} c\) \(\lambda_{\mathrm{C}, \mathrm{p}}\) \(2.10308910336(64) \times 10^{-16}\) \(\(\mathrm{~m}\) \(3.1 \times 10^{-10}\)
    \(\quad\) proton Compton wavelength \(\lambda_{\mathrm{C}, \mathrm{p}}\) \(1.32140985539(40) \times 10^{-15}\) \([\mathrm{~m}]^{\dagger}\) \(3.1 \times 10^{-10}\)
    proton rms charge radius \(r_{\mathrm{p}}\) \(8.414(19) \times 10^{-16}\) \(\mathrm{~m}\) \(2.2 \times 10^{-3}\)
    proton magnetic moment \(\mu_{\mathrm{p}}\) \(1.41060679736(60) \times 10^{-26}\) \(\mathrm{~J} \mathrm{~T}^{-1}\) \(4.2 \times 10^{-10}\)
    \(\quad \) to Bohr magneton ratio \(\mu_{\mathrm{p}} / \mu_{\mathrm{B}}\) \(1.52103220230(46) \times 10^{-3}\)   \(3.0 \times 10^{-10}\)
    \(\quad\) to nuclear magneton ratio \(\mu_{\mathrm{p}} / \mu_{\mathrm{N}}\) \(2.79284734463(82)\)   \(2.9 \times 10^{-10}\)
    proton g-factor \(2 \mu_{\mathrm{p}} / \mu_{\mathrm{N}}\) \(g_{\mathrm{p}}\) \(5.5856946893(16)\)   \(2.9 \times 10^{-10}\)
    proton-neutron magnetic moment ratio \(\mu_{\mathrm{p}} / \mu_{\mathrm{n}}\) \(-1.45989805(34)\)   \(2.4 \times 10^{-7}\)
    shielded proton magnetic moment
    \(\mu_{\mathrm{p}}^{\prime}\) \(1.410570560(15) \times 10^{-26}\) \(\mathrm{~J} \mathrm{~T}^{-1}\) \(1.1 \times 10^{-8}\)
    \(\left(\mathrm{H}_2 \mathrm{O} \text {, sphere, } 25^{\circ} \mathrm{C}\right)\)        
    \(\quad\) to Bohr magneton ratio \(\mu_{\mathrm{p}}^{\prime} / \mu_{\mathrm{B}}\) \(1.520993128(17) \times 10^{-3}\)   \(1.1 \times 10^{-8}\)
    \(\quad\) to nuclear magneton ratio \(\mu_{\mathrm{p}}^{\prime} / \mu_{\mathrm{N}}\) \(2.792775599(30)\)   \(1.1 \times 10^{-8}\)
    proton magnetic shielding correction        
    \(1-\mu_{\mathrm{p}}^{\prime} / \mu_{\mathrm{p}}\left(\mathrm{H}_2 \mathrm{O}\right., sphere, \left.25^{\circ} \mathrm{C}\right)\) \(\sigma_{\mathrm{p}}^{\prime}\) \(2.5689(11) \times 10^{-5}\)   \(4.2 \times 10^{-4}\)
    proton gyromagnetic ratio 2 \(\mu_{\mathrm{p}} / \hbar\) \(\gamma_{\mathrm{p}}\) \(2.6752218744(11) \times 10^8\) \(\mathrm{~s}^{-1} \mathrm{~T}^{-1}\) \(4.2 \times 10^{-10}\)
        \(42.577 478 518(18)\) \(\mathrm{MHz} \mathrm{T}^{-1}\) \(4.2 \times 10^{-10}\)
    shielded proton gyromagnetic ratio        
    \(2 \mu_{\mathrm{p}}^{\prime} / \hbar\left(\mathrm{H}_2 \mathrm{O}\right., sphere, \left.25^{\circ} \mathrm{C}\right)\) \(\gamma_{\mathrm{p}}^{\prime}\) \(2.675153151(29) \times 10^8\) \(\mathrm{~s}^{-1} \mathrm{~T}^{-1}\) \(1.1 \times 10^{-8}\)
        \(42.57638474(46)\) \(\mathrm{MHz} \mathrm{T}^{-1}\) \(1.1 \times 10^{-8}\)

    Table \(\PageIndex{9}\): Neutron, n

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    neutron mass \(m_{\mathrm{n}}\) \(1.67492749804(95) \times 10^{-27}\)
    \(\mathrm{kg}\)
    \(5.7 \times 10^{-10}\)
        \(1.008 664 915 95(49)\) \(\mathrm{u}\) \(4.8 \times 10^{-10}\)
    \(\quad \)energy equivalent \(m_{\mathrm{n}} c^2\) \(1.50534976287(86) \times 10^{-10}\)
    \(\mathrm{J}\) \(5.7 \times 10^{-10}\)
        \(939.565 420 52(54)\) \(\mathrm{MeV}\) \(5.7 \times 10^{-10}\)
    neutron-electron mass ratio \(m_{\mathrm{n}} / m_{\mathrm{e}}\) \(1838.68366173(89)\)   \(4.8 \times 10^{-10}\)
    neutron-muon mass ratio \(m_{\mathrm{n}} / m_\mu\) \(8.89248406(20)\)   \(2.2 \times 10^{-8}\)
    neutron-tau mass ratio \(m_{\mathrm{n}} / m_\tau\) \(0.528779(36)\)   \(6.8 \times 10^{-5}\)
    neutron-proton mass ratio \(m_{\mathrm{n}} / m_{\mathrm{p}}\) \(1.00137841931(49)\)   \(4.9 \times 10^{-10}\)
    neutron-proton mass difference \( m_{\mathrm{n}}-m_{\mathrm{p}}\) \(2.30557435(82) \times 10^{-30
    }\)
    \(\mathrm{kg}\)
    \(3.5 \times 10^{-7}\)
        \(1.38844933(49) \times 10^{-3}\) \(\mathrm{u}\) \(3.5 \times 10^{-7}\)
    \(\quad \)energy equivalent \( \left(m_{\mathrm{n}}-m_{\mathrm{p}}\right) c^2\) \(2.07214689(74) \times 10^{-13}\)
    \(\mathrm{J}\)
    \(3.5 \times 10^{-7}\)
        \(1.29333236(46)\) \(\mathrm{MeV}\) \(3.5 \times 10^{-7}\)
    neutron molar mass \(N_{\mathrm{A}} m_{\mathrm{n}}\) \( M(\mathrm{n}), M_{\mathrm{n}}\) \(1.00866491560(57) \times 10^{-3}\) \(\mathrm{~kg} \mathrm{~mol}^{-1}\) \(5.7 \times 10^{-10}\)
    reduced neutron Compton wavelength \(\hbar / m_{\mathrm{n}} c\)
    \( \lambda_{\mathrm{C}, \mathrm{n}\) \(2.1001941552(12) \times 10^{-16}\)
    \(\mathrm{m
    }\)
    \(5.7 \times 10^{-10}\)
    neutron Compton wavelength \( \lambda_{\mathrm{C}, \mathrm{n}\) \(1.31959090581(75) \times 10^{-15}\) \([\mathrm{m}]^{\dagger}\) \(5.7 \times 10^{-10}\)
    neutron magnetic moment

    \( \mu_{\mathrm{n}}\)

    \(-9.6623651(23) \times 10^{-27}\) \(\mathrm{~J} \mathrm{~T}^{-1}\) \(2.4 \times 10^{-7}\)
    \(\quad \)to Bohr magneton ratio \( \mu_{\mathrm{n}} / \mu_{\mathrm{B}}\) \(-1.04187563(25) \times 10^{-3}\)   \(2.4 \times 10^{-7}\)
    \(\quad \)to nuclear magneton ratio \( \mu_{\mathrm{n}} / \mu_{\mathrm{N}}\) \(-1.91304273(45)\)   \(2.4 \times 10^{-7}\)
    neutron g-factor \(2 \mu_{\mathrm{n}} / \mu_{\mathrm{N}}\) \( g_{\mathrm{n}}\) \(-3.82608545(90)\)   \(2.4 \times 10^{-7}\)
    neutron-electron magnetic moment ratio \(\mu_{\mathrm{n}} / \mu_{\mathrm{e}}\) \(1.04066882(25) \times 10^{-3}\)   \(2.4 \times 10^{-7}\)
    neutron-proton magnetic moment ratio \(\mu_{\mathrm{n}} / \mu_{\mathrm{p}}\) \(-0.68497934(16)\)   \(2.4 \times 10^{-7}\)
    neutron to shielded proton magnetic        
    \(\quad \) moment ratio \(\left(\mathrm{H}_2 \mathrm{O}\right., sphere, \left.25^{\circ} \mathrm{C}\right)\) \(\mu_{\mathrm{n}} / \mu_{\mathrm{p}}^{\prime}\) \(-0.68499694(16)\)   \(2.4 \times 10^{-7}\)
    neutron gyromagnetic ratio \(2\left|\mu_{\mathrm{n}}\right| / \hbar\) \(\gamma_{\mathrm{n}}\) \(1.83247171(43) \times 10^8\) \(\mathrm{~s}^{-1} \mathrm{~T}^{-1}\) \(2.4 \times 10^{-7}\)
        \(29.1646931(69)\) \(\mathrm{MHz} \mathrm{T}^{-1}\) \(2.4 \times 10^{-7}\)

    Table \(\PageIndex{10}\): Deuteron, d

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    deuteron mass \( m_{\mathrm{d}}\) \( 3.3435837768(10) \times 10^{-27}\) kg \( 3.1 \times 10^{-10}\)
        \( 2.013553212544(15)\) u \( 7.4 \times 10^{-12}\)
    iivalent \( m_{\mathrm{d}} c^2 \) \( 3.00506323491(94) \times 10^{-10}\) J \( 3.1 \times 10^{-10}\)
    deuteron-electron mass ratio \( m_{\mathrm{d}} / m_{\mathrm{e}} \) \( 3670.4829676555(63)\) MeV \( 3.1 \times 10^{-10}\)
    deuteron-proton mass ratio \( m_{\mathrm{d}} / m_{\mathrm{p}} \) \( 1.9990075012699(84)\)   \( 1.7 \times 10^{-11}\)
    deuteron molar mass \(N_{\mathrm{A}} m_{\mathrm{d}}\) \( M(\mathrm{~d}), M_{\mathrm{d}} \) \( 2.01355321466(63) \times 10^{-3}\)   \( 4.2 \times 10^{-12}\)
    deuteron rms charge radius \( r_{\mathrm{d}} \) \( 2.12778(27) \times 10^{-15}\) \( \mathrm{~kg} \mathrm{~mol}^{-1} \( 3.1 \times 10^{-10}\)
    deuteron magnetic moment \( \mu_{\mathrm{d}} \) \( 4.330735087(11) \times 10^{-27}\) \mathrm{~m}^{-1} \( 1.3 \times 10^{-4}\)
    to Bohr magneton ratio \( \mu_{\mathrm{d}} / \mu_{\mathrm{B}} \) \( 4.669754568(12) \times 10^{-4}\)   \( 2.6 \times 10^{-9}\)
    to nuclear magneton ratio \( \mu_{\mathrm{d}} / \mu_{\mathrm{N}} \) \( 0.8574382335(22)\)   \( 2.6 \times 10^{-9}\)
    deuteron g-factor \(\mu_{\mathrm{d}} / \mu_{\mathrm{N}}\) \( g_{\mathrm{d}} \) \( 0.8574382335(22)\)   \( 2.6 \times 10^{-9}\)
    deuteron-electron magnetic moment ratio \( \mu_{\mathrm{d}} / \mu_{\mathrm{e}} \) \( -4.664345550(12) \times 10^{-4}\)   \( 2.6 \times 10^{-9}\)
    deuteron-proton magnetic moment ratio \( \mu_{\mathrm{d}} / \mu_{\mathrm{p}} \) \( 0.30701220930(79)\)   \( 2.6 \times 10^{-9}\)
    deuteron-neutron magnetic moment ratio \( \mu_{\mathrm{d}} / \mu_{\mathrm{n}} \) \( -0.44820652(11)\)   \( 2.6 \times 10^{-9}\)
             

    Table \(\PageIndex{11}\): Triton, t

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    triton mass \( m_{\mathrm{t}}\) \( 5.0073567512(16) \times 10^{-27}\) kg \( 3.1 \times 10^{-10}\)
        \( 3.01550071597(10)\) u \( 3.4 \times 10^{-11}\)
    energy equivalent \( m_{\mathrm{t}} c^2\) \( 4.5003878119(14) \times 10^{-10}\) J \( 3.1 \times 10^{-10}\)
        \( 2808.92113668(88)\) MeV \( 3.1 \times 10^{-10}\)
    triton-electron mass ratio \( m_{\mathrm{t}} / m_{\mathrm{e}}\) \( 5496.92153551(21)\) \( 3.8 \times 10^{-11}\)
    triton-proton mass ratio \( m_{\mathrm{t}} / m_{\mathrm{p}}\)     \( 3.4 \times 10^{-11}\)
    triton molar mass \( N_{\mathrm{A}} m_{\mathrm{t}}\) \( M(\mathrm{t}), M_{\mathrm{t}}\) \( 3.01550071913(94) \times 10^{-3}\) \( \mathrm{~kg} \mathrm{~mol}^{-1}\) \( 3.1 \times 10^{-10}\)
    triton magnetic moment \( \mu_{\mathrm{t}}\) \( 1.5046095178(30) \times 10^{-26}\) \( \mathrm{~J} \mathrm{~T}^{-1}\) \( 2.0 \times 10^{-9}\)
    to Bohr magneton ratio \( \mu_{\mathrm{t}} / \mu_{\mathrm{B}}\) \( 1.6223936648(32) \times 10^{-3}\) \( 2.0 \times 10^{-9}\)
    to nuclear magneton ratio \( \mu_{\mathrm{t}} / \mu_{\mathrm{N}}\) \( 2.9789624650(59)\)   \( 2.0 \times 10^{-9}\)
    triton g-factor \( 2 \mu_{\mathrm{t}} / \mu_{\mathrm{N}}\) \( g_{\mathrm{t}}\)     \( 2.0 \times 10^{-9}\)
             

    Table \(\PageIndex{12}\): Helion, h

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    helion mass \( m_{\mathrm{h}}\) \( 5.0064127862(16) \times 10^{-27}\) kg \( 3.1 \times 10^{-10}
    25 \times 10^{-11} \)
        \( 3.014932246932(74)\)   \( 2.5 \times 10^{-11}\)
    energy equivalent \( m_{\mathrm{h}} c^2\) \( 4.4995394185(14) \times 10^{-10}\) J \( 3.1 \times 10^{-10}\)
        \( 2808.39161112(88)\) MeV \( 3.1 \times 10^{-10}\)
    helion-electron mass ratio \( m_{\mathrm{h}} / m_{\mathrm{e}}\) \( 5495.88527984(16)\)   \( 2.9 \times 10^{-11}\)
    helion-proton mass ratio \( m_{\mathrm{h}} / m_{\mathrm{p}}\) \( 2.993152671552(70)\)   \( 2.4 \times 10^{-11}\)
    helion molar mass \( N_{\mathrm{A}} m_{\mathrm{h}}\) \( M(\mathrm{~h}), M_{\mathrm{h}}\) \( 3.01493225010(94) \times 10^{-3}\) \( \mathrm{~kg} \mathrm{~mol}^{-1}\) \( 3.1 \times 10^{-10}\)
    helion magnetic moment \( \mu_{\mathrm{h}}\) \( -1.07461755198(93) \times 10^{-26}\) \( \mathrm{~J} \mathrm{~T}^{-1}\) \( 8.7 \times 10^{-10}\)
    to Bohr magneton ratio \( \mu_{\mathrm{h}} / \mu_{\mathrm{B}}\) \( -1.15874098083(94) \times 10^{-3}\)   \( 8.1 \times 10^{-10}\)
    to nuclear magneton ratio \( \mu_{\mathrm{h}} / \mu_{\mathrm{N}}\) \( -2.1276253498(17)\)   \( 8.1 \times 10^{-10}\)
    helion g-factor \( 2 \mu_{\mathrm{h}} / \mu_{\mathrm{N}}\) \( g_{\mathrm{h}}\) \( -4.2552506995(34)\)   \( 8.1 \times 10^{-10}\)
    shielded helion magnetic moment
    (gas, sphere, \( 25^{\circ} \mathrm{C} )\)
    \( \mu_{\mathrm{h}}^{\prime}\) \( -1.07455311035(93) \times 10^{-26}\) \( \mathrm{~J} \mathrm{~T}^{-1} \( 8.7 \times 10^{-10}\)
    to Bohr magneton ratio \( \mu_{\mathrm{h}}^{\prime} / \mu_{\mathrm{B}}\) \( -1.15867149457(94) \times 10^{-3}\)   \( 8.1 \times 10^{-10}\)
    to nuclear magneton ratio \( \mu_{\mathrm{h}}^{\prime} / \mu_{\mathrm{N}}\) \( -2.1274977624(17)\)   \( 8.1 \times 10^{-10}\)
    shielded helion to proton magnetic
    moment ratio (gas, sphere, \( 25^{\circ} \mathrm{C} )\)
    shielded helion to shielded proton magnetic
    \( \mu_{\mathrm{h}}^{\prime} / \mu_{\mathrm{p}}\) \( -0.76176657721(66)\)   \( 8.6 \times 10^{-10}\)
    moment ratio (gas / \( \mathrm{H}_2 \mathrm{O}, spheres, 25^{\circ} \mathrm{C} )\) \( \mu_{\mathrm{h}}^{\prime} / \mu_{\mathrm{p}}^{\prime}\) \( -0.761 7861334(31)\)   \( 4.0 \times 10^{-9}\)
    shielded helion gyromagnetic ratio        
    \( 2\left|\mu_{\mathrm{h}}^{\prime}\right| / \hbar \text { (gas, sphere, } 25^{\circ} \mathrm{C} \text { ) }\) \( \gamma_{\mathrm{h}}^{\prime}\) \( 2.0378946078(18) \times 10^8\) \( \mathrm{s}^{-1} \mathrm{~T}^{-1}\) \( 8.7 \times 10^{-10}\)
        \( 32.434100033(28)\) \( \mathrm{MHz} \mathrm{T}^{-1}\) \( 8.7 \times 10^{-10}\)

    Table \(\PageIndex{13}\): Alpha particle, \(\alpha\)

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    alpha particle mass \(m_\alpha\) \(6.6446573450(21) \times 10^{-27}\) kg \(3.1 \times 10^{-10}\)
    energy equivalent   \(4.001506179129(62)\) u \(1.6 \times 10^{-11}\)
      \(m_\alpha c^2\) \(5.9719201997(19) \times 10^{-10}\) J \(3.1 \times 10^{-10}\)
    alpha particle to electron mass ratio   \(3727.3794118(12)\) MeV \(3.1 \times 10^{-10}\)
    alpha particle to proton mass ratio \(m_\alpha / m_{\mathrm{e}}\) \(7294.29954171(17)\)   \(2.4 \times 10^{-11}\)
    alpha particle rms charge radius \(m_\alpha / m_{\mathrm{p}}\) 3.972599690252(70)\)   \(1.8 \times 10^{-11}\)
    alpha particle molar mass \(N_{\mathrm{A}} m_\alpha\) \(r_\alpha\) \(1.6785(21) \times 10^{-15}\) m \(1.2 \times 10^{-3}\)
      \(M(\alpha), M_\alpha\) \(4.0015061833(12) \times 10^{-3}\) \(\mathrm{~kg} \mathrm{~mol}^{-1} \(3.1 \times 10^{-10}\)
             

    Table \(\PageIndex{14}\): Physicochemical Constants

    Quantity Symbol Value Unit Relative std.
    uncert. u_{\mathrm{r}}
    Avogadro constant
    \( N_{\mathrm{A}}\) \( 6.02214076 \times 10^{23}\) \( \mathrm{~mol}^{-1}\) exact
    Boltzmann constant k \( 1.380649 \times 10^{-23}\) \( \mathrm{~J} \mathrm{~K}^{-1}\) exact
        \( 8.617333262 \ldots \times 10^{-5}\) \( \mathrm{eV} \mathrm{K}^{-1}\) exact
      k / h \( 2.083661912 \ldots \times 10^{10}\) \( \mathrm{~Hz} \mathrm{~K}^{-1}\) exact
      k / h c \( 69.50348004 \ldots\) \( \left[\mathrm{m}^{-1} \mathrm{~K}^{-1}\right]^{\dagger}\) exact
    atomic mass constant        
    \( m_{\mathrm{u}}=\frac{1}{12} m\left({ }^{12} \mathrm{C}\right)=2 h c R_{\infty} / \alpha^2 c^2 A_{\mathrm{r}}(\mathrm{e})\) \( m_{\mathrm{u}} \) \( 1.66053906892(52) \times\) 10^{-27}\) kg \( 3.1 \times 10^{-10}\)
    equivalent energy \( m_{\mathrm{u}} c^2\) \)\( 1.49241808768(46) \times 10^{-10}\) J \( 3.1 \times 10^{-10}\)
        \( 931.49410372(29)\) MeV \( 3.1 \times 10^{-10}\)
    molar mass constant\( { }^{\|}\) \( M_{\mathrm{u}}\) \( 1.00000000105(31) \times 10^{-3}\) \( \mathrm{~kg} \mathrm{~mol}^{-1}\) \( 3.1 \times 10^{-10}\)
    molar mass" of carbon-12 \( A_{\mathrm{r}}\left({ }^{12} \mathrm{C}\right) M_{\mathrm{u}}\) \( M\left({ }^{12} \mathrm{C}\right)\) \( 12.0000000126(37) \times 10^{-3}\) \( \mathrm{~kg} \mathrm{~mol}^{-1}\) \( 3.1 \times 10^{-10}\)
    molar Planck constant \( N_{\mathrm{A}} h\) \( 3.990312712 \ldots \times 10^{-10}\) \( \mathrm{~J} \mathrm{~Hz}^{-1} \mathrm{~mol}^{-1}\) exact
    molar gas constant \( N_{\mathrm{A}} k\) R \( 8.314462618 \ldots\) \( \mathrm{J} \mathrm{mol}^{-1} \mathrm{~K}^{-1}\) exact
    Faraday constant \( N_{\mathrm{A}} e\) F \( 96485.33212 \ldots\) \( \mathrm{C} \mathrm{mol}^{-1}\) exact
    standard-state pressure   \( 100000\) Pa exact
    standard atmosphere   \( 101325\) Pa exact
    molar volume of ideal gas R T / p        
    T=273.15 \( \mathrm{~K}, p=100 \mathrm{kPa}\)
    or standard-state pressure
    \( V_{\mathrm{m}}\) \( 22.71095464 \ldots \times 10^{-3}\) \( \mathrm{~m}^3 \mathrm{~mol}^{-1}\) exact
    Loschmidt constant \( N_{\mathrm{A}} / V_{\mathrm{m}}\)
    molar volume of ideal gas R T / p
    \( n_0\) \( 2.651645804 \ldots \times 10^{25}\) \( \mathrm{~m}^{-3}\) exact
    \( T=273.15 \mathrm{~K}, p=101.325 \mathrm{kPa}\)
    or standard atmosphere
    \( V_{\mathrm{m}}\) \( 22.41396954 \ldots \times 10^{-3}\) \(\mathrm{~m}^3 \mathrm{~mol}^{-1}\) exact
    Loschmidt constant \( N_{\mathrm{A}} / V_{\mathrm{m}}\) \( n_0\) \( 2.686780111 \ldots \times 10^{25}\) \(\mathrm{~m}^{-3}\) exact
    Sackur-Tetrode (absolute entropy) constant**        

    \(\frac{5}{2}+\ln \left[\left(m_{\mathrm{u}} k T_1 / 2 \pi \hbar^2\right)^{3 / 2} k T_1 / p_0\right]\)

    \(T_1=1 \mathrm{~K}, p_0=100 \mathrm{kPa} \)
    or standard-state pressure

    \( S_0 / R\) \(-1.15170753496(47)\)   \(4.1 \times 10^{-10}\)
    \( T_1=1 \mathrm{~K}, p_0=101.325 \mathrm{kPa} \)
    or standard atmosphere
      \(-1.16487052149(47)\)   \(4.0 \times 10^{-10}\)
    Stefan-Boltzmann constant
    \( \left(\pi^2 / 60\right) k^4 / \hbar^3 c^2\)
    \( \sigma\) \(5.670374419 \ldots \times 10^{-8}\) \(\mathrm{~W} \mathrm{~m}^{-2} \mathrm{~K}^{-4}\) exact
    first radiation constant for spectral        
    radiance \( 2 h c^2 \mathrm{sr}^{-1}\) \( c_{1 \mathrm{~L}}\) \( 1.191042972 \ldots \times 10^{-16}\) \( \left[\mathrm{~W} \mathrm{~m}^2 \mathrm{sr}^{-1}\right]^{\dagger}\) exact
    first radiation constant \( 2 \pi h c^2=\pi \mathrm{sr} c_{1 \mathrm{~L}}\) \( c_1\) \( 3.741771852 \ldots \times 10^{-16}\) \( \left[\mathrm{~W} \mathrm{~m}^2\right]^{\dagger}\) exact
    second radiation constant h c / k \( c_2\) \( 1.438776877 \ldots \times 10^{-2}\) \( [\mathrm{~m} \mathrm{~K}]^{\dagger}\) exact
    Wien displacement law constants        
    \( b=\lambda_{\max } T=c_2 / 4.965114231 \ldots\) b \( 2.897771955 \ldots \times 10^{-3}\) \( [\mathrm{~m} \mathrm{~K}]^{\dagger}\) exact
    \( b^{\prime}=\nu_{\max } / T=2.821439372 \ldots c / c_2\) \( b^{\prime}\) \( 5.878925757 \ldots \times 10^{10}\) Hz K exact
             

    * The energy of a photon with frequency \(\nu\) expressed in unit Hz is \(E=h \nu\) in J . Unitary time evolution of the state of this photon is given by \(\exp (-i E t / \hbar)|\varphi\rangle\), where \(|\varphi\rangle\) is the photon state at time \(t=0\) and time is expressed in unit s. The ratio \(E t / \hbar\) is a phase.

    \({ }^{\dagger}\) The symbol \([\mathrm{m}]\) denotes \(\mathrm{m} /(\mathrm{Hz} \mathrm{s})\). If angles are dimensionless, as in the current SI , then \(\mathrm{Hz} \mathrm{s}=1\). If angles have a dimension, then \(\mathrm{Hz} \mathrm{s}=\) cycle.
    ‡ Value recommended by the Particle Data Group (Workman, et al., 2022).

    \({ }^8\) Based on the ratio of the masses of the W and Z bosons \(m_{\mathrm{W}} / m_{\mathrm{Z}}\) recommended by the Particle Data Group (Workman, et al., 2022). The value for \(\sin ^2 \theta_{\mathrm{W}}\) they recommend, which is based on a variant of the modified minimal subtraction \((\overline{\mathrm{MS}})\) scheme, is \(\sin ^2 \hat{\theta}_{\mathrm{W}}\left(M_{\mathrm{Z}}\right)=0.23122(4)\).

    \({ }^{\text {II }}\) This and other constants involving \(m_\tau\) are based on \(m_\tau c^2\) in MeV recommended by the Particle Data Group (Workman, et al., 2022). atomic mass constant and u is the unified atomic mass unit. Moreover, the mass of particle \(X\) is \(m(X)=A_{\mathrm{r}}(X) \mathrm{u}\) and the molar mass of \(X\) is \

    (M(X)=A_{\mathrm{r}}(X) M_{\mathrm{u}}\), where \(M_{\mathrm{u}}=N_{\mathrm{A}} \mathrm{u}\) is the molar mass constant and \(N_{\mathrm{A}}\) is the Avogadro constant.

    \({ }^{* *}\) The entropy of an ideal monoatomic gas of relative atomic mass \(A_{\mathrm{r}}\) is given by \(S=S_0+\frac{3}{2} R \ln A_{\mathrm{r}}-R \ln \left(p / p_0\right)+\frac{5}{2} R \ln (T / \mathrm{K})\).


    66.25: Fundamental Physical Constants — Extensive Listing is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts.

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