# Picometre

Picometre

A picometre (American spelling: picometer, symbol pm) is a unit of length in the metric system, equal to one trillionth (1/1,000,000,000,000) of a metre, which is the current SI base unit of length. It can be written in scientific notation as 1&times;10−12 m (engineering notation) or nowrap|1 E-12 m (exponential notation) — both meaning nowrap|1 m / 1,000,000,000,000.

It equals a millionth of a micrometre (formerly called a micron), and was formerly called micromicron, stigma, or bicron. [cite book | title = Dictionary of Distances | author = Elena Deza and Michel Marie Deza | publisher = Elsevier | year = 2006 | isbn = 0444520872 | url = http://books.google.com/books?id=I-PQH8gcOjUC&pg=PA347&dq=stigma+bicron&lr=&ei=tYjISJz5HaaktAPJkqjkBQ&sig=ACfU3U3U2S3gikmIt4r9RO8dM3GYllujSA ] The symbol µµ was once used for it. [How Many? A Dictionary of Units of Measurement; Russ Rowlett and the University of North Carolina at Chapel Hill; http://www.unc.edu/~rowlett/units/dictB.html]

It equals a hundredth of an Ångström, an internationally recognized non-SI unit of length.

ee also

*Metric system
*Orders of magnitude (length)
*Conversion of units, for comparison with other units of length.

References

Wikimedia Foundation. 2010.

### Look at other dictionaries:

• Picomètre — Représentation simplifiée d un atome d hélium (le plus petit de tous les atomes), dont le diamètre calculé est de 62 picomètres. Un picomètre (symbole : pm) est une unité de longueur du système métrique, équivalent à… …   Wikipédia en Français

• picometre — noun 10 of a metre. Symbol: pm …   Wiktionary

• picometre — noun a metric unit of length equal to one trillionth of a meter • Syn: ↑picometer, ↑micromicron • Hypernyms: ↑metric linear unit • Part Holonyms: ↑angstrom, ↑angstrom unit, ↑A …   Useful english dictionary

• 1 picometre — 1 pm redirects here. For the time, see 12 hour clock. To help compare different orders of magnitude this page lists lengths between 10−12 m and 10−11 m (1 pm and 10 pm). Distances shorter than 1 pm 1 pm = 1 picometre = 1,000 femtometres 1 pm =… …   Wikipedia

• Metre — This article is about the unit of length. For other uses of metre or meter , see meter (disambiguation). 1 metre = SI units 100 cm 1000 mm US customary / Imperial units 3.2808 ft 39.370 in The metre (or meter), symbol m, is… …   Wikipedia

• 100 femtometres — To help compare different orders of magnitudes this page lists lengths between 10−13 m and 10−12 m (100 fm and 1 pm).Distances shorter than 100 fm *100 femtometres till 1 picometre rangeDistances longer than 1 pmee also*Femtometre *Picometre… …   Wikipedia

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