Nanometre
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American spelling) is a unit of length in the metric system, equal to one billionth (short scale) of a metre (0.000000001 m). The name combines the SI prefix nano- (from the Ancient Greek νάνος, nanos, "dwarf") with the parent unit name metre (from Greek μέτρον, metrοn, "unit of measurement"). It can be written in scientific notation as 1×10−9 m, in engineering notation as 1 E−9 m, and as simply 1/1000000000 metres. When used as a prefix for something other than a unit of measure (as in "nanoscience"), nano refers to nanotechnology, or phenomena typically occurring on a scale of nanometres (see nanoscopic scale).
Nanometre-1