Multiplication factor Name Symbol
10 ^6 micro m
10 ^9 nano n
10 ^12 pico p
aOnly to be used for some volume and area units.
Some Other Units
The%symbol is often used and, unless stated otherwise, it is often meant to
signify kg/100 kg.
For the temperaturescale, SI rules allow the use of degrees Celsius,
symbol 8 C, but not for temperature intervals; nor can 8 C it be used with a
prefix. For example: cool the liquid to 158 C at a rate of 10 mK?s^1.
For angles, often the ‘‘degree’’ is used, symbol 8.
For volumes, the unit liter can be used (10^3 m^3 ), symbol l. However,
the symbol L often is used for liter without a prefix, to avoid confusion with
the numeral 1; however, use ml rather than mL, etc.
Confusion can readily arise for concentrations of chemical substances.
The unit ‘‘molar’’ (often used symbol M) means mol/L or kmol?m^3 , not
mol/m,^3 which may be considered a violation of SI rules.