Ångström

Named after the Swedish physicist A J Ångström (1814-74). It is an old unit used for measuring the wavelength of electromagnetic radiation including visible light and X-rays. The unit has since been superseded by the nanometre but is still used in crystallography.

1Å = 10^-10m

Atomic diameters range between 1 and 2 Angstroms.

See also: Fermi, Micron, Nanometre.