mass
'no magic to the mole'
amount
molar mass
concentration
solution volume
gas volume
molar gas volume
Avogadro
constant, L
number of
entities, N
Now try the following question.
A10. PREFIXES FOR SUB-MULTIPLES & MULTIPLES OF SI UNITS
In instances where the base S.I. units above are of an inappropriate size, it may be more convenient to use the decimal sub-multiple or multiple form of the coherent SI unit.
They are useful for expressing the values of quantities that are much larger than or much smaller than the coherent unit. The CGPM has approved the prefixes below.
However, when prefixes are used with SI units, the resulting units are no longer coherent, because the prefix introduces a numerical factor other than one. Prefixes may be used with any of the 29 SI units with special names except for the base unit kilogram. For historical reasons, the kilogram already incorporates the multiple ‘kilo’. That must be removed before other multiples or sub-multiples are attached - as in mg or µg or ng - since both compound prefix names and symbols are unacceptable.
see also A further short history of the SI prefixes
Richard J C Brown, NPL, TW11 0LW, UK
Department of Physics, University of Surrey, GU2 7XH, UK
2023 Metrologia 60 013001
doi.org/10.1088/1681-7575/ac6afd
The next question concerns the writing of SI prefixes for sub-multiples and multiples of units.
