The symbols for the base units of the SI are defined here.
The fundamental and atomic constants shown are:
 RK |
von Klitzing constant |
| KJ |
Josephson constant |
|
RK-90 and KJ-90 |
the conventional values of these constants, introduced on 1 January 1990 |
|
NA |
Avogadro constant |
|
F |
Faraday constant |
|
G |
Newtonian constant of gravitation |
|
m12C |
mass of 12C |
|
me |
electron mass |
R |
Rydberg constant |
|
h |
Planck constant |
|
c |
speed of light in vacuum |
 0 |
magnetic constant |
 |
fine-structure constant |
|
R |
molar gas constant |
|
k |
Boltzmann constant |
|
e |
elementary charge |
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