ангстрем(= о́нгстрём – ångström; a metric unit of length equal to one ten billionth of a meter [0.0001 micron]; used to specify wavelengths of electromagnetic radiation wikipedia.org)
онгстрем(= ангстрем; a metric unit of length equal to one ten billionth of a meter [0.0001 micron]; used to specify wavelengths of electromagnetic radiation)