The angstrom or ångstrom is a metric unit of length equal to 10⁻¹⁰ m; that is, one ten-billionth of a metre, 0.1 nanometre, or 100 picometres. Its symbol is Å, a letter of the Swedish alphabet. The ångstrom is not a part of the SI system of units, but it can be considered part of the metric system in general

Uses:

The angstrom is used in solid-state physics, chemistry, and crystallography. The unit is used to cite wavelengths of light, chemical bond length, and the size of microscopic structures using the electron microscope. X-ray wavelengths may be given in angstroms, as these values typically range from 1 to 10 Å.