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Glite Dictionary
femtometer

femtometer

9.9
A unit of length equal to one millionth of a millionth of a meter used to measure very small distances
  • noun
  • /ˈfɛmtoʊˌmɛtər/
  • Specialized
translation icon : femtómetro
  • The wavelength of some gamma rays is measured in femtometers, indicating their extremely short length.

Examples

  • However, 1 fm may also be read as "one femtometer" where "femto-" is a general prefix representing (10-15).

    Blog text (9)

  • The size of a proton is about a femtometer, all right.

  • (1 fm = 10^-15 m is called a fermi or a femtometer, according to taste.)

    Academic text (2003)

  • A typical diameter of a nucleus is around femtometers.

  • In particle physics, measurements are often in femtometers to discuss subatomic scales.

Synonyms

fermi
vsfemtometer
  • Specialized
1 9.9

A very small unit of length equal to one quadrillionth of a meter used to measure very small particles

adds particle physics to its domain rather than only nuclear

How Long

meter
  • Specialized
621 1.0
millimeter
  • Specialized
140 2.5
micrometer
  • Specialized
2 4.8
nanometer
  • Specialized
7 4.8
picometer
  • Specialized
7.2
femtometer
  • Specialized
9.9

Surface Forms

femtometer singular
femtometers plural

Morphology

femtometer = meter (semi-transparent) = femto + meter

The word is built regularly from the metric prefix 'femto-' plus 'meter', but the prefix is specialized and not likely to be known by an average learner.

Etymology

Femtometer comes from the parts femto- and meter. The femto- part was taken from a Danish word meaning 'fifteen' and marks the very small number 10 to the minus 15, and meter is the common unit for length, so a femtometer is a very tiny meter used to measure things inside atoms.