Picometre
| Picometre | |
|---|---|
SI | |
| Unit of | length |
| Symbol | pm |
| Conversions | |
| 1 pm in ... | ... is equal to ... |
| US units | 3.9370×10−11 in |
Look up picometre in Wiktionary, the free dictionary.
The picometre (international
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
ångström
, an internationally known (but non-SI) unit of length.
Use
The picometre's length is of an order so small that its application is almost entirely confined to
quantum physics, chemistry, and acoustics. Atoms are between 62 and 520 pm in diameter, and the typical length of a carbon–carbon single bond is 154 pm. Smaller units still may be used to describe smaller particles (some of which are the components of atoms themselves), such as hadrons and the upper limits of possible size for fermion
point particles.
The Laser Interferometer Space Antenna (LISA) probe is planned for launch in 2034 to directly detect gravitational waves and will measure relative displacements with a resolution of 20 picometres over a distance of 2.5 gigametres, yielding a strain sensitivity of better than 1 part in 1020.
References
- ^ "Atomic radius". WebElements: the periodic table on the web.
- ISBN 0-444-52087-2.
- ^ Rowlett, Russ (2018). "How Many? A Dictionary of Units of Measurement".