Femtometre
Unit of length / From Wikipedia, the free encyclopedia
For examples of things measuring between one and ten femtometres, see 1 femtometre.
The femtometre (American spelling femtometer) symbol fm[1][2][3] (derived from the Danish and Norwegian word femten 'fifteen', Ancient Greek: μέτρον, romanized: metrοn, lit. 'unit of measurement') is a unit of length in the International System of Units (SI) equal to 10−15 metres, which means a quadrillionth of one metre. This distance is sometimes called a fermi and was so named in honour of Italian naturalized to American physicist Enrico Fermi, as it is a typical length-scale of nuclear physics.
Quick Facts General information, Unit system ...
Femtometre | |
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General information | |
Unit system | SI |
Unit of | length |
Symbol | fm |
Conversions | |
1 fm in ... | ... is equal to ... |
SI base units | 1×10−15 m |
Natural units | 6.1877×1019 ℓP 1.8897×10−5 a0 |
imperial/US units | 3.9370×10−14 in |
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