Home Page Faculty & Research Seminars Graduate Studies Undergraduate Studies Latest News Newsletter Department Info
Chair's Message Research Instrumentation Diversity Alumni Industrial Relations Open Positions Contact Info
Physical Constants

Fundamental Physical Constants / Naturkonstanten

English/German

Exponent (base 10) of decimal numbers: e n = 10^n . Units are separated by spaces, positive numbers denote powers, all units to the right of the slash are in the denominator (negative powers).

Planck constant / Plancksches Wirkungsquantum h
6.6260755e-34 J s
h/(2 pi) = 1.05457266e-34 J s
Boltzmann constant / Boltzmannsche Konstante k_B
1.380658e-23 J/K
Elementary charge / Elementarladung e
1.60217733e-19 C
Avogadro number / Avogadrosche Zahl N_A
6.0221367e23 particles/mol
Speed of light / Lichtgeschwindigkeit c
2.99792458e8 m/s
Permeability of vacuum / Permeabilität des Vakuums mu_0
mu_0 = 4 pi e-7 T2 m3/J
12.566370614e-7 T2 m3/J
Permittivity of vacuum / Dielektrizitätskonstante des Vakuums epsilon_0
epsilon_0 = 1 / (mu_0 c^2)
8.854187817e-12 C2/J m
Fine structure constant / Feinstrukturkonstante 1 / alpha
137.0359895
Electron rest mass / Elektronenruhemasse m_e
9.1093897e-31 kg
Proton rest mass / Protonenruhemasse m_p
1.6726231e-27 kg
Neutron rest mass / Neutronenruhemasse m_n
1.6749286e-27 kg
Bohr magneton / Bohrsches Magneton mu_B
mu_B = eh/(4 pi m_e)
9.2740154e-24 J/T
Nuclear magneton / Kernmagneton mu_N
mu_N = eh/(4 pi m_p)
5.0507866e-27 J/T
Free electron g factor / g-Faktor des freien Elektrons g_e
2.002319304386
Free electron gyromagnetic ratio / gyromagnetisches Verhältnis des freien Elektrons gamma_e
gamma_e = 2 pi g_e mu_B / h
1.7608592e11 1/s T
gamma_e/(2 pi) = 28.024944 GHz/T
Electron magnetic moment / magnetisches Moment des Elektrons mu_e
mu_e = -(1/2) g_e mu_B
-9.2847701e-24 J/T
Proton gyromagnetic ratio (H2O) / gyromagnetisches Verhältnis der Protonen in Wasser gamma_p
2.67515255e8 1/s T
gamma_p/(2 pi) = 42.576375 MHz/T
Proton magnetic moment / magnetisches Moment des Protons mu_p
1.41060761e-26 J/T
Proton-electron ratios / Proton-Elektron-Verhältnisse
m_p/m_e = 1836.152701
mu_e/mu_p = 658.2106881
gamma_e/gamma_p = 658.2275841 (protons in water)

Charge-to-mass ratio for electron / Ladungs-Masse-Verhältnis des Elektrons e / m_e

1.75880e11 C/kg
Atomic mass unit / Einheit der Atommasse amu
1.66057e-27 kg
Bohr radius / Bohrscher Radius a_0
5.29177e-11 m
Electron radius / Elektronenradius r_e
2.81792e-15 m
Gas constant / Gaskonstante R
R = N_A k_B
8.3143 m2 kg/s2 K mol
Molar volume / Molvolumen V_mol
22.41383 m3/kmol
Faraday constant / Faradaysche Konstante F
F = N_A e
9.64846e4 C/mol
Proton g factor (Lande factor) / g-Faktor des Protons g_H
5.585
Gravitational constant / Gravitationskonstante G
6.6732e-11 m3/kg s2
Acceleration due to gravity / Erdbeschleunigung g
9.80665 m/s2
Compton wavelength of the electron / Compton-Wellenlänge des Elektrons lambda_c
lambda_c = h / (m_e c)
2.42631e-12 m

Further Useful Constants / Weitere nützliche Konstanten

Atomic energy unit / atomare Energieeinheit Hartree
1 Hartree = e^2 /(4 pi epsilon_0 a_0)
1 Hartree = 2.625501e+06 J/mol (approx. 627.5 kcal/mol)

Useful Conversion Factors / Nützliche Umrechnungsfaktoren

NMR (Nuclear Magnetic Resonance)

Proton Larmor frequency
nu_p = gamma_p/(2 pi) B
nu_p = 42.5764 MHz/T (H2O)

EPR (Electron Paramagnetic Resonance, ESR)

Electron Larmor frequency
nu_e = gamma_e/(2 pi) g/g_e B
nu_e [GHz] = 13.9962 g B[T]
g = 0.07144775 nu_e[GHz]/B[T]
g = 3.04199 nu_e[GHz]/nu_p[MHz]
B [T] = 0.0234872 nu_p[MHz]
Conversion of Units
1 G = 0.1 mT
1 T = 10 kG
1 mT = 10 G
A[MHz] = 2.80249 (g/g_e) A[G]
A[MHz] = 28.0249 (g/g_e) A[mT]
A[MHz] = 13.9962 g A[mT]
A[MHz] = 2.99792e4 A[1/cm]
A[1/cm] = 0.333564e-4 A[MHz]
A[1/cm] = 4.66863e-4 g A[mT]
Faculty Message
Welcome New Grad Students
Ph.D Program
Our Alumni
Student Profiles
Financial Assistance
Application Information
Admissions Open House
Events!
Information & Resources
Safety Requirements
Graduate Student Life