electron

American  

[ih-lek-tron] / ɪˈlɛk trɒn /

noun

• electrons
  plural

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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electron British  

/ ɪˈlɛktrɒn /

noun

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

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electron Scientific  

/ ĭ-lĕk′trŏn′ /

1. A stable elementary particle in the lepton family having a mass at rest of 9.107 × 10 ^{- 28} grams and a negative electric charge of approximately 1.602 × 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.

2. Compare positron See also electromagnetism elementary particle ion See Table at subatomic particle

3. A positron or a negatron.

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electron Cultural  

1. 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).

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Discover More

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

Other Word Forms

Noun Inflected Forms

• electrons
  plural

Etymology

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 ( electric )

Compare meaning

How does electron compare to similar and commonly confused words? Explore the most common comparisons:

• proton vs. electron

Explanation

If you take chemistry, you will learn about electrons. Electrons are the smallest of the particles that make up an atom, and they carry a negative charge. The number of protons and electrons is equal in a neutral atom. The hydrogen atom, for example, has just one electron and one proton. The uranium atom, on the other hand, has 92 protons, and therefore, 92 electrons. An electron is so small that it cannot be seen with the naked eye, but neither can the atom itself.

Example Sentences

See Examples For:

electron electrons

In the mass range examined by the researchers, these particles would be extraordinarily light, roughly 19 to 21 orders of magnitude lighter than an electron.

From Science Daily ● Sep. 6, 2026

The researchers eventually made progress using electron cryotomography, a high-resolution 3D imaging method capable of revealing structures at the scale of a millionth of a millimeter.

From Science Daily ● Sep. 3, 2026

Additional experiments involving electron microscopy, molecular biology, and electrophysiology revealed another surprise.

From Science Daily ● Aug. 20, 2026

More recently, researchers have found them in materials that also support more complicated forms of collective electron behavior, including magnetism and superconductivity, in which electrons pair together and move through a material without friction.

From Science Daily ● Aug. 20, 2026

They don’t go all the way to zero distance from the electron when they calculate the electron’s true mass and charge; they stop short of zero at an arbitrary distance.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

One is cyclotron energy, which comes from the orbital motion of electrons through a magnetic field.

From Science Daily ● Sep. 5, 2026

An ultrathin diamond wafer converts CEBAF's electrons into a beam of high-energy photons with parallel spins.

From Science Daily ● Sep. 2, 2026

As scientists pursue quantum computers, ultra-efficient electronics, and other advanced technologies, a detailed understanding of how electrons behave inside superconductors will become increasingly important.

From Science Daily ● Aug. 31, 2026

Regions corresponding to the crests contain more electrons, while the troughs contain fewer.

From Science Daily ● Aug. 20, 2026

Nor would these, together with electrons, form separate, well-defined atoms.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

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