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Constant | Symbol | Value
--- | --- | ---
Speed of light in vacuum | c | 2.998×10 8≈3×10 8 m/s
Gravitational constant | G | 6.67×10−11 N⋅m 2/k g 2
Boltzmann’s constant | K | 1.38×10−23 J/K
Elementary charge | e | 1.60×10−19 C
Permittivity of free space | ϵ 0 | 8.85×10−12≈1 36 π×10−9 F/m
Permeability of free space | μ 0 | 4 π×10−7 H/m
Electron mass | m e | 9.11×10−31 kg
Proton mass | m p | 1.67×10−27 kg
Planck’s constant | h | 6.63×10−34 J⋅s
Intrinsic impedance of free space | η 0 | 376.7≈120 π Ω