What is the smallest metric unit?

Answer 1

The SI, or metric, system uses a set of prefixes to show the multiple or fraction of the base unit, eg kilo- is a multiple of one thousand, so a kilometre is 1000 metres; milli- is one thousandth, so a millimetre is one one thousandth of a metre.

The prefix for the smallest fraction is yocto, 1 yoctometre (ym) is 1 x 10-24 metres, or 0.000 000 000 000 000 000 000 001 metres.

Answer 2

As such there is no smallest metric length, but the smallest in general (scientific) use is the nano metre (1 nm = 10-9 m = 0.000000001 m)

The metric base unit of length is the metre (m) which is then prefixed by a multiplier which makes it bigger or smaller.

The prefix multipliers to make it smaller are:

deci- (d) = x 10-1

centi- (c) = x 10-2

milli- (m) = x 10-3

(these three are in general use, though rarely the first)

micro- (µ) = x 10-6

nano- (n) = x 10-9

(these two are used in scientific and nano- is generally the smallest used, however, it is theoretically possible to use:)

pico- (p) = x 10-12

femto- (f) = x 10-15

atto- (a) = x 10-18

zepto- (z) = x 10-21

yocto- (y) = x 10-24

eg 1 pm (1 pico metre) would be 10-12 m or 0.000000000001 m long.

The diameter of an atom nucleus is about 10-14m = 10 x 10-15 m = 10 fm (10 femto metres) wide.

Answer 3

There is no shortest unit. There is only one unit; the meter. All other 'units' are multiplications or divisions of a meter.

Answer 4

micrometer
picometer
sicometer
nanometer

Answer 5

micro