The nanometre is often used to express dimensions on an atomic scale: the diameter of a helium atom, for example, is about 0.1 nm, and that of a ribosome is about 20 nm. The nanometre is also commonly used to specify the wavelength of electromagnetic radiation near the visible part of the spectrum: visible light ranges from around 400 to 800 nm. The angstrom, which is equal to 0.1 nm, was formerly used for these purposes.
^Svedberg, The; Nichols, J. Burton (1923). "Determination of the size and distribution of size of particle by centrifugal methods". Journal of the American Chemical Society45 (12): 2910–2917. doi:10.1021/ja01665a016.
^Sweden, The; Rinde, Herman (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 Society46 (12): 2677–2693. doi:10.1021/ja01677a011.
^Terzaghi, Karl (1925). Erdbaumechanik auf bodenphysikalischer Grundelage. Vienna: Franz Deuticke. p. 32.