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

Ion, ī′on, n. one of the components into which an electrolyte is broken up on electrolysis—the Anion, the electro-negative component, chemically attacking the anode, and the Cation, the electro-positive component, the cathode.

From Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) by Various

They also get them between Ceylan and Comori, between Borneo and Anion, and in Cochinchina.

From The Philippine Islands, 1493-1898 — Volume 27 of 55 1636-37 Explorations by Early Navigators, Descriptions of the Islands and Their Peoples, Their History and Records of the Catholic Missions, as Related in Contemporaneous Books and Manuscripts, Showing the Political, Economic, Commercial and Religious Conditions of Those Islands from Their Earliest Relations with European Nations to the Close of the Nineteenth Century by Robertson, James Alexander

The terms Anion and Cation, which he applied to the constituents of the decomposed electrolyte, and the term Ion, which included both anions and cations, are still less frequently employed.

From Faraday as a Discoverer by Tyndall, John