# anion

/ˈæˌnaɪɔn/ (US) · /ˈænaɪən/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/anion
Updated: 2026-05-30

## Definition

a negatively charged particle in a chemical solution. It moves toward the positive side of an electric current.

For teachers: an atom or molecule that has gained one or more electrons, giving it a negative charge. It is attracted to the anode in an electrolytic cell.

## Examples

- Chloride is a common anion found in salt water.
- In the electrolysis of water, the anion moves toward the positive electrode while the cation moves toward the negative one.
- The stability of the resulting compound depends on the relative sizes and charges of the anion and cation, as smaller ions with higher charges tend to form more robust ionic bonds.

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