femto- [FEM toh]

(Danish and Norwegian: fifteen; a decimal prefix used in the international metric system for measurements)

It is used in the metric [decimal] system as quadrillionth [U.S.] and thousand-billionth part [U.K.], 10-15 [0.000 000 000 000 001]. The metric symbol for femto- is f.


femtoampere
femtogram, fg
A unit of mass equal to 0.000 000 000 000 001 grams or 10-15 grams. Symbol: fg
femtojoule
femtoliter
femtometer
femtomole
femtosecond
A femtosecond is one millionth of a nanosecond or 10-15 of a second and is a measurement sometimes used in laser technology.
femtovolt, fV
1. A unit of voltage equal to 10-15 volts.
2. A unit of potential equal to one quadrillionth of a volt, or one thousandth of a nanosecond.
femtowatt (fW)
The quadrillionth [U.S.] and thousand-billionth part [U.K.], 10-15 [0.000 000 000 000 001] of a watt.

Related "metric" families: yotta; zetta; exa; peta; tera; giga; mega; kilo; hecto; deka; deci; centi; milli; micro; nano; pico; atto; zepto; yocto.