electron charge

physics

Also known as: ε, elementary charge, fundamental charge

Written and fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Mar 7, 2025 • Article History

Key People:: Robert Millikan

Related Topics:: electron; electric charge; physical constant; Millikan oil-drop experiment; charge conservation

On the Web:: University of Pittsburgh - PhilSci-Archive - Is an electron a charge cloud? A reexamination of Schr¨odinger’s charge density hypothesis (PDF) (Mar. 07, 2025)

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electron charge, (symbol e), fundamental physical constant expressing the naturally occurring unit of electric charge, equal to 1.602176634 × 10⁻¹⁹ coulomb. In addition to the electron, all freely existing charged subatomic particles thus far discovered have an electric charge equal to this value or some whole-number multiple of it. Quarks, which are always bound within larger subatomic particles such as protons and neutrons, have charges of 1/3 or 2/3 of this value.

This article was most recently revised and updated by Erik Gregersen.