Quantity

Symbol

Value

SI unit

Speed of light in a vacuum

c

3.00 x 10⁸

m/s

Permittivity of a vacuum

8.85 x 10^-12

F/m

Permeability of a vacuum

4pi x 10

N/A²

Elementary charge

e

1.60 x 10^-19

C

Electron rest mass

m_e

9.11 x 10^-31

kg

Proton rest mass

m_p

1.67 x 10^-27

kg

Neutron rest mass

m_n

1.67 x 10^-27

kg

Planck's constant

h

6.63 x 10^-34

J·s

Coulomb's constant

k_e

8.99 x 10⁹

N·m²/C²

Avogadro's constant

N_A

6.02 x 10²³

1/gmol

Molar gas constant

R

8.31

J/mol·K

Boltzmann's constant

k_B

1.38 x 10^-23

J/K

Stefan-Boltzmann constant

5.67 x 10^-8

W/m²·K⁴

Molar volume of ideal gas at STP

V

22.4

L/mol

Rydberg constant

R

1.10 x 10⁷

1/m

Bohr radius

a₀

5.29 x 10^-11

M

Electron Compton wavelength

h/m_ec

2.43 x 10^-12

M

Gravitational Constant

G

6.67 x 10^-11

m³/kg·s²

Standard gravity

g

9.80

m/s²

Radius of the Earth (at the equator)

R_E

6.38 x 10⁶

M

Mass of the Earth

M_E

5.98 x 10²⁴

Kg

Radius of the Moon

R_m

1.74 x 10⁶

M

Mass of the Moon

M_m

7.36 x 10²²

Kg

Electron charge magnitude

e

1.602 x 10^-19

C

Permeability of free space

₀

Pi x 10^-7

T·m/A

Permittivity of free space

₀

8.85 x 10^-12

C²/(N·m²⁾

Universal gas constant

R

8.31

J/(mol·K)