For examples of things measuring between one and ten femtometres, see 1 femtometre.
Femtometre
The helium atom and perspective magnitudes
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
6.1877×1019ℓP 1.8897×10−5a0
imperial/US units
3.9370×10−14 in
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.
^Conversion from fermi to femtometer (fm) Archived May 23, 2011, at the Wayback Machine
^"Units: F". Unc.edu. Archived from the original on 2018-07-09. Retrieved 2015-11-04.
^"Nuclear Size and Shape" (PDF). Archived from the original on 2012-04-25.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
The femtometre (American spelling femtometer) symbol fm (derived from the Danish and Norwegian word femten 'fifteen', Ancient Greek: μέτρον, romanized: metrοn...
FM, heavy truck range Adobe FrameMaker, document processing software Femtometre (fm), a unit of length Femtomolar (fM), a unit of molar concentration...
ångström (0.1 nm) has been used commonly instead of the nanometre. The femtometre, used mainly in particle physics, is sometimes called a fermi. For large...
109 m Gm gigametre 10−12 m pm picometre 1012 m Tm terametre 10−15 m fm femtometre 1015 m Pm petametre 10−18 m am attometre 1018 m Em exametre 10−21 m zm...
which is the SI base unit of length. The picometre is one thousand femtometres, one thousandth of a nanometre (1/1000 nm), one millionth of a micrometre...
particularly the proton distribution. The proton radius is about one femtometre = 10−15 metre. It can be measured by the scattering of electrons by the...
by two independent methods, which converged to a value of about 0.877 femtometres (1 fm = 10−15 m). This value was challenged by a 2010 experiment using...
strong force is effective over a very short range (usually only a few femtometres (fm); roughly one or two nucleon diameters) and causes an attraction...
force is powerfully attractive between nucleons at distances of about 0.8 femtometre (fm, or 0.8×10−15 m), but it rapidly decreases to insignificance at distances...
barn (b) is a unit of area used in nuclear physics equal to one hundred femtometres squared (100 fm2 = 10−28 m2). The are (a) is a unit of area equal to...
approximately equal to 1.07 A 3 {\displaystyle 1.07{\sqrt[{3}]{A}}} femtometres, where A {\displaystyle A} is the total number of nucleons. This is much...
force is powerfully attractive between nucleons at distances of about 1 femtometre (fm, or 10−15 metres), but it rapidly decreases to insignificance at distances...
subparticles, they have a meaningful physical size, a diameter of roughly one femtometre (10−15 m), which is about 0.6 times the size of a proton or neutron. All...
rapidly with distance, and is thus very short-range (effectively a few femtometres). It manifests as a force between the "colorless" hadrons, and is known...
both positively charged. In order to fuse, the nuclei must be within 1 femtometre (1 × 10−15 metres) of each other, where quantum-tunnelling effects permit...
ell ≡ 45 in (In England usually) = 1.143 m fathom ftm ≡ 6 ft = 1.8288 m femtometre fm ≡ 1×10−15 m ≡ 1×10−15 m fermi fm ≡ 1×10−15 m ≡ 1×10−15 m finger ≡...
is 4-5 orders of magnitude larger than the dimension of the nucleus (femtometres). The free neutrons in a beam travel in a plane wave; for those that...
below. Fermi (unit), unit of length in particle physics equivalent to the femtometre Fermi arc, a phenomenon in superconductivity Fermi constant, constant...
into the quark-gluon matter. This was determined to be 3 GeV per cubic femtometre, which showed agreement with lattice QCD. Furthermore, the experiment...
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