# ammonia vs ammonium

> English confusable word pair

## The two words

### ammonia
*noun · IPA /əˈməʊ.nɪ.ə/ · frequency rank #18,007*
A gaseous, toxic compound of hydrogen and nitrogen, NH₃, with a pungent smell and taste.

### ammonium
*noun · IPA /əˈmoʊni.əm/ · frequency rank #27,717*
The univalent NH₄⁺ cation, derived by the protonation of ammonia

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/ammonia-vs-ammonium