Which non-SI unit of length is 1 x 10-10 m (one ten-billionth of a metre)?
Ångström . However, the ångström sign is also normalized into The Unicode consortium recommends to use the regular letter (00C5). Before digital typesetting, the ångström (or ångström unit) was sometimes written as "A.U." (also an abbreviation of the astronomical unit). This use is evident in Bragg's paper on the structure of ice, which gives the c- and a-axis lattice constants as 4.52 A.U. and 7.34 A.U., respectively. Nowadays the atomic unit of length (a.u.) usually stands for bohrs, not ångströms. Ångström The ångström (,; ) or angstrom is a unit of length equal to (one ten-billionth of a metre) or 0.1
Unit of length Unit of length A unit of length refers to any discrete, pre-established length or distance having a constant magnitude which is used as a reference or convention to express linear dimension. The most common units in modern use are U.S. customary units in the United States and metric units elsewhere. British Imperial units are still used for some purposes in the United Kingdom and some other countries. The metric system is sub-divided into SI and non-SI units. The base unit in the International System of Units (SI) is the metre, defined as "the length of the path travelled by light