The angstrom is a unit of length equal to 10⁻¹⁰ m; that is, one ten-billionth of a metre, a hundred-millionth of a centimetre, 0.1 nanometre, or 100 picometres. The unit is named after the Swedish physicist Anders Jonas Ångström. It was originally spelled with Swedish letters, as Ångström and later as ångström. The latter spelling is still listed in some dictionaries, but is now rare in English texts. Some popular US dictionaries list only the spelling angstrom.
