anion

American  

[an-ahy-uhn] / ˈænˌaɪ ən /

noun

Physical Chemistry.

1. a negatively charged ion, as one attracted to the anode in electrolysis.

2. any negatively charged atom or group of atoms (opposed to cation).

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anion British  

/ ˌænaɪˈɒnɪk, ˈænˌaɪən /

noun

1. a negatively charged ion; an ion that is attracted to the anode during electrolysis Compare cation

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anion Scientific  

/ ăn′ī′ən /

1. An ion with net negative charge, having more electrons than protons. In electrolysis, anions migrate to a positively charged anode.

2. Compare cation

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Other Word Forms

• anionic adjective
• anionically adverb

Etymology

Origin of anion

Coined in 1834 by English polymath Willaim Whewell (1794–1866) and popularized by English chemist Michael Faraday (1791–1867) in his collection Experimental Researches in Electricity; from Greek, neuter of aniṓn “going up,” present participle of aniénai “to go up,” from an- an- ³ + iénai “to go”; modeled on anode ( def. )

Explanation

An anion is an atom that has more electrons than protons—in other words, an anion is an atom with a negative charge. In a chemistry class, you'll come across the word ion frequently. That's an atom that either has extra electrons, giving it a negative charge, or is missing electrons, resulting in a positive charge. The negatively charged ions are called anions, and the positively charged ions are cations. In Greek, anion means "thing going up," which describes the movement anions make during the chemical process of electrolysis.

Example Sentences

Whether chloronitramide anion will be linked to any cancers or has other adverse health risks will be assessed in future work by academics and regulatory agencies, such as the U.S.

From Science Daily • Nov. 21, 2024

"Our research in anion and cation binding can apply to not only cystic fibrosis, but a host of other channel diseases caused by defective ion channels."

From Science Daily • Oct. 10, 2023

His plan is to explore anion batteries that provide the necessary components without using limited minerals like the ones lithium batteries use and that could potentially increase how much energy a battery can hold.

From Washington Times • Nov. 12, 2022

Neither the cation nor the anion of this salt undergo acid-base ionization; the only process generating hydronium ions is the autoprotolysis of water.

From Textbooks • Feb. 14, 2019

DEFINITION: A salt is a substance formed by the union of the anion of an acid with the cation of a base.

From An Elementary Study of Chemistry by McPherson, William