What are the seven fundamental units?

1 Answer
Jun 2, 2018

The SI units for the seven fundamental measurable qualities are:

  • #"A"#, ampere, a unit of electrical current
  • #"cd"#, candela, a unit of luminous intensity
  • #"K"#, kelvin, a unit of absolute temperature
  • #"kg"#, kilogram, a unit of mass
  • #"m"#, meter, a unit of distance
  • #"mol"#, mole, a unit of quantity/counting
  • #"s"#, second, a unit of time

Of course, we also have prefixes that can be appended to all of these as we wish, to express them in nicer numerical magnitudes, e.g.

  • #"pm"#, picometers, for atomic radii
  • #"ns"#, nanoseconds, for some first-order mean lifetime #tau -= k^(-1)# of a fluorescent molecule
  • #"mg"#, milligrams, for typical solid/powder drug prescriptions
  • #"mm"#, millimeters, for measurements using a caliper