The angstrom unit is traditionally denoted by the capital letter A with a small circle above. It's called Angstrom Sign Å. There are two symbols with similar writing in Unicode: the one you see on this page [U:212B], and the Latin capital letter A with a circle [U:00C5] from the [URL /blocks/latin-1-supplement/ Latin-1 Supplement] block.

Angstrom is a unit of length that is used worldwide. However, it doesn't form a part of the International System of Units (SI). One angstrom is equal to 1 µm (one millionth of a meter). This is approximately the diameter of an electron's orbit, the distance between bonds in a crystalline lattice. As for the SI system, the nearest unit to the angstrom is the nanometer [U:339A].