[ ih-lek-tron ]
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  1. Also called negatron. Physics, Chemistry. an elementary particle that is a fundamental constituent of matter, having a negative charge of 1.602 × 10−19 coulombs, a mass of 9.108 × 10−31 kilograms, and spin of ½, and existing independently or as the component outside the nucleus of an atom.

  2. Electricity. a unit of charge equal to the charge on one electron.

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Origin of electron

Term first suggested in 1891 by Irish physicist G. J. Stoney (1826–1911); electr(ic) + -on (from the names of charged particles, as ion, cation, anion) with perhaps accidental allusion to Greek ḗlektron amber (see electric)

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British Dictionary definitions for electron


/ (ɪˈlɛktrɒn) /

  1. a stable elementary particle present in all atoms, orbiting the nucleus in numbers equal to the atomic number of the element in the neutral atom; a lepton with a negative charge of 1.602 176 462 × 10 –19 coulomb, a rest mass of 9.109 381 88 × 10 –31 kilogram, a radius of 2.817 940 285 × 10 –15 metre, and a spin of 1/2

Origin of electron

C19: from electro- + -on

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for electron


[ ĭ-lĕktrŏn′ ]

  1. A stable elementary particle in the lepton family having a mass at rest of 9.107 X 10-28 grams and a negative electric charge of approximately 1.602 X 10-19 coulombs. Electrons orbit about the positively charged nuclei of atoms in distinct orbitals of different energy levels, called shells. Electrons are the primary charge carriers in electric current. Compare positron. See also electromagnetism elementary particle ion. See Table at subatomic particle.

  2. A positron or a negatron.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for electron


[ (i-lek-tron) ]

An elementary particle with a negative charge and a very small mass. Electrons are normally found in orbits around the nucleus of an atom. The chemical reactions that an atom undergoes depend primarily on the electrons in the outermost orbits (the valence electrons).

Notes for electron

The movement of large numbers of electrons through conductors constitutes an electric current.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.