Orders of magnitude (length) | Metre
Picometre
The picometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: pm) or picometer (American spelling) is a unit of length in the International System of Units (SI), equal to 1×10−12 m, or one trillionth (1/1000000000000) of a metre, which is the SI base unit of length. The picometre is one thousand femtometres, one thousandth of a nanometre (1/1000 nm), one millionth of a micrometre (also known as a micron), one billionth of a millimetre, and one trillionth of a metre. The symbol μμ was once used for it. It is also one hundredth of an ångström, an internationally known (but non-SI) unit of length. (Wikipedia).
