Picometre

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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 1×10⁻¹² m (engineering notation) or 1 E-12 m (exponential notation) — both meaning 1 m / 1,000,000,000,000.

It equals a millionth of a micrometre (formerly called a micron), and was formerly called micromicron or bicron. (The symbol µµ was apparently used both for this^[1] and for the nanometre.)
It equals a hundredth of an Ångström, an internationally recognized non-SI unit of length.

Standard prefixes for the SI units of measure

Multiples	Name		deca-	hecto-	kilo-	mega-	giga-	tera-	peta-	exa-	zetta-	yotta-
	Symbol		da	h	k	M	G	T	P	E	Z	Y
	Factor	100	101	102	103	106	109	1012	1015	1018	1021	1024
Subdivisions	Name		deci-	centi-	milli-	micro-	nano-	pico-	femto-	atto-	zepto-	yocto-
	Symbol		d	c	m	µ	n	p	f	a	z	y
	Factor	100	10−1	10−2	10−3	10−6	10−9	10−12	10−15	10−18	10−21	10−24

[edit] See also

• 1 E-12 m
• SI
• SI prefix
• Metric system
• Orders of magnitude (length)
• Conversion of units, for comparison with other units of length.

[edit] References

1. ^ 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

v • d • e SI units of length picometre <<< nanometre <<< micrometre <<< millimetre < centimetre < decimetre < metre < decametre < hectometre < kilometre <<< megametre <<< gigametre