# alum vs atom

> English confusable word pair

## The two words

### alum
*noun · IPA /ˈæl.əm/ · frequency rank #20,832*
An astringent salt, usually occurring in the form of pale crystals, much used in the dyeing and tanning trade and in certain medicines, and now understood to be a double sulphate of potassium and aluminium (K₂SO₄·Al₂(SO₄)₃·24H₂O).

### atom
*noun · IPA /ˈætəm/ · frequency rank #10,813*
The smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.

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