Thanks Max, I learn something every day....

Another commonly used unit of length is the Angstrom (1 Angstrom = 10-10 m = 0.1 nanometer). Atoms are roughly Angstroms in size (a hydrogen atom is about 1 A in diameter, a carbon atom is about 2 A in diameter). You might read about Angstroms, and you should just immediately think of them as a tenth of a nanometer.