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cation

American  
[kat-ahy-uhn, -on] / ˈkætˌaɪ ən, -ɒn /
Or kation

noun

Physical Chemistry.
  1. a positively charged ion that is attracted to the cathode in electrolysis.

  2. any positively charged atom or group of atoms (opposed to anion).


cation British  
/ ˈkætaɪən /

noun

  1. a positively charged ion; an ion that is attracted to the cathode during electrolysis Compare anion

"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

cation Scientific  
/ kăt′ī′ən /
  1. An ion with net positive charge, having more protons than electrons. In electrolysis, cations migrate to a negatively charged cathode.

  2. 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."

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Vocabulary lists containing cation

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.

See Examples For:

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

Their analysis revealed the persistence of halogen bonds between the cation and the anion guiding the sequential dynamics.

From Science Daily ● Jun. 4, 2024

This effect was confirmed through ab initio molecular dynamics simulations, which revealed the migration pathways of protons near the Sc cation when transporting across the material.

From Science Daily ● May 29, 2024

Both contain iron, it is true, but neither possess the properties of the cation Fe+++, but rather those of the complex anion of which they form a part.

From The Mechanism of Life by Stéphane Leduc

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