cation
Americannoun
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a positively charged ion that is attracted to the cathode in electrolysis.
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any positively charged atom or group of atoms (opposed to anion).
noun
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An ion with net positive charge, having more protons than electrons. In electrolysis, cations migrate to a negatively charged cathode.
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Compare anion
Other Word Forms
Etymology
Origin of cation
1825–35; < Greek katión going down (neuter of katiṓn, present participle of kateînai ), equivalent to kat- cat- ( def. ) + -i- go + -on neuter present participle suffix
Explanation
In science, a cation is an ion, or charged particle, with a positive charge. In other words, a cation has more protons than electrons. If you come across the word ion in a chemistry or physics class, cation and anion won't be far behind. An ion is a particle that has an electrical charge. When an ion's charge is negative, it's more specifically called an anion, and when it's positive, you can use the term cation. The Greek source is kation, which means "going down."
Vocabulary lists containing cation
Break It Down: Cata
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Structure and Properties of Matter - Middle School
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Chemistry: Structure and Properties of Matter
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Researchers focused on infrared light emitted by a molecule known as trihydrogen cation.
From Science Daily ● May 29, 2026
He recommends treating the issue at the water point of entry to the home with cation exchange resin, a type of ion exchange.
From Los Angeles Times ● Jul. 22, 2024
This marks the first quantitative assessment and analysis of cation mixing defects, a domain previously restricted to qualitative examination.
From Science Daily ● May 13, 2024
While defect ordering has been observed numerous times in perovskite oxides, the same cannot be said about hybrid halide perovskites, composed of an organic cation, a metal cation, and a halide anion.
From Science Daily ● Apr. 17, 2024
The remainder of the molecule, which usually consists of a single atom, is the cation.
From An Elementary Study of Chemistry by McPherson, William
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
