Different lengths as in respect to theelectromagnetic spectrum, measured by the metre and its derived scales. The nanometre is often used to express dimensions on an atomic scale and mostly in themolecular scale.
The nanometre was formerly known as the "millimicrometre" – or, more commonly, the "millimicron" for short – since it is1/1000 of amicrometer. It was often denoted by the symbolmμ or, more rarely, asμμ (however,μμ should refer to amillionth of a micron).[1][2][3]
The name combines theSI prefixnano- (from theAncient Greekνάνος,nanos, "dwarf") with the parent unit namemetre (from Greekμέτρον,metron, "unit of measurement").
The nanometre is often used to express dimensions on an atomic scale: the diameter of ahelium atom, for example, is about 0.06 nm, and that of aribosome is about 20 nm. The nanometre is also commonly used to specify thewavelength ofelectromagnetic radiation near the visible part of thespectrum: visible light ranges from around 400 to 700 nm.[4] Theångström, which is equal to 0.1 nm, was formerly used for these purposes.
^abSvedberg T, Nichols JB (1923). "Determination of the size and distribution of size of particle by centrifugal methods".Journal of the American Chemical Society.45 (12):2910–2917.doi:10.1021/ja01665a016.
^Svedberg T, Rinde H (1924). "The ulta-centrifuge, a new instrument for the determination of size and distribution of size of particle in amicroscopic colloids".Journal of the American Chemical Society.46 (12):2677–2693.doi:10.1021/ja01677a011.
^Terzaghi K (1925).Erdbaumechanik auf bodenphysikalischer Grundlage. Vienna: Franz Deuticke. p. 32.
