Base quantities, units, and symbols
from the international system (IS)
Quantity
Symbol
Units
Symbol
Absolute temperature
T
kelvin
K
Amount of substance
n
mole
mol
Electric current
I
ampere
A
Length
ℓ
meter
m
Luminous intensity
Iv
candela
cd
Mass
m
kilogram
kg
Time
t
second
s
Physical and chemical constants
Avogadro constant
N Av = 6.02 # 10
23
mol
−1
Boltzmann constant
k = 1.38 # 10
−23
J K
−1
Electron charge
e = 1.6 # 10
−19
C
Faraday constant
F = 96 480 C mol
−1
Ideal gas constant
R = 8.314 J mol
−1
K
−1
Imaginary unit
j
2 = −1
Pi
π = 3.14159
Speed of light
c = 3 # 10
8
m s
−1
Standard pressure
P
0 = 10
5
Pa
Vacuum permittivity
ε 0 = 8.85 # 10
−12
F m
−1
1