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

Marcus had discovered a calculation that violated the law of conservation of energy, a bedrock scientific principle, tucked inside a new theory on electron behavior.

From Los Angeles Times ● Jul. 17, 2026

That doesn’t mean every electron comes from solar or wind, but it does mean Google can claim to be offsetting its power use with low-carbon-emissions sources that use almost no water.

From The Wall Street Journal ● Jul. 3, 2026

In ferromagnets, neighboring electron spins point in the same direction, creating an external magnetic field.

From Science Daily ● Jun. 23, 2026

Eventual analysis with scanning electron microscopy at the Canadian Museum of Nature allowed researchers to confirm it as a probable embolomere.

From Barron's ● Jun. 18, 2026

A zero-dimensional electron has an infinite mass and charge because it is a singularity; as you get closer and closer to it, your measurements zoom off to infinity.

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

The Marcus Theory, as it came to be known, provides a mathematical way to determine how fast or slow, or in what direction, electrons jump between molecules without breaking chemical bonds.

From Los Angeles Times ● Jul. 17, 2026

Quantum many body physics has long relied on different models to explain how impurities, such as exotic electrons or atoms, interact with surrounding particles.

From Science Daily ● Jul. 9, 2026

Another unusual feature is that gallium forms `covalent bonds,' in which atoms share electrons.

From Science Daily ● Jul. 9, 2026

At these extremely low temperatures, electrons behave in a much more orderly way, making it easier to observe quantum phenomena, where matter acts like waves rather than ordinary particles.

From Science Daily ● Jul. 2, 2026

In reality, however, even when the electrons are sent one at a time, the fringes still appear.

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

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