Fermi (unit)

E88967

The fermi is a unit of length equal to one femtometer (10⁻¹⁵ meter), commonly used in nuclear and particle physics to express sizes of atomic nuclei and subatomic particles.


Statements (37)
Predicate Object
instanceOf non-SI unit
unit of length
alternativeName fermi
approximateNuclearSizeExample typical atomic nucleus radius is a few fermis
belongsToSystem cgs-based nuclear physics units
category units of length
definition 1 fermi = 1 femtometer
1 fermi = 10^-15 meter
dimension length
etymology named to honor physicist Enrico Fermi
fieldOfUse high-energy physics
nuclear engineering
nuclear physics
particle physics
largerThan Planck length
namedAfter Enrico Fermi
orderOfMagnitude 10^-15 meter
relatedUnit angstrom
nanometer
scaleDescription subnuclear length scale
scaleRelativeToMeter 1 fermi = 0.000000000000001 meter
SIEquivalent femtometer
smallerThan angstrom
nanometer
status non-SI unit accepted for use in nuclear physics context
symbol fm
typicalMagnitudeInNuclearPhysics 1–10 fermis for nuclear radii
typicalScale neutron radius
nuclear radius
proton radius
usageContext experimental nuclear physics
particle scattering experiments
theoretical nuclear physics
usedFor nuclear distance scales
sizes of atomic nuclei
sizes of nucleons
sizes of subatomic particles

Referenced by (1)
Subject (surface form when different) Predicate
Enrico Fermi
hasEponym

Please wait…