what is pm in length
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 metric system, equal to 6988100000000000000â 1Ã10â12 m, or one trillionth (17012100000000000000â 1000000000000) of a metre, which is the SI base unit of length.