Atom Means Uncuttable, and Then It Was Cut
An atom is the smallest unit of a chemical element. Its Greek name asserts something that turned out to be untrue.
An atom is the smallest particle of a chemical element that retains its properties. The name is a claim that physics later disproved: Greek *atomos* means uncuttable, from *a-*, not, plus *temnein*, to cut. Democritus argued in the fifth century BCE that matter must be made of indivisible particles, and the word kept his assertion — until the electron was found in 1897 and the nucleus split in 1932. Science rarely renames things when they turn out otherwise, so we still call them atoms.
- An element's smallest unit. *A carbon atom.*
- Atomos — uncuttable. *Atomos.*
- Democritus — the early theorist. *Democritus.*
- Atomic — the adjective. *Atomic.*
- Greek — *temnein*, to cut. *The root.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | atom | An atom. |
| Plural | atoms | Atoms. |
| Adjective | atomic | Atomic. |
| Verb | atomise | Atomise. |
| Greek | atomos | Uncuttable. |
- Water has three atoms per molecule.Chemistry.
- Atomos means uncuttable.Etymology.
- The nucleus was split in 1932.History.
Names that outlived their meaning
- Atom — uncuttable, but divisible after all
- Oxygen — acid-former, though it does not form all acids
- Malaria — bad air, though mosquitoes carry it
- Influenza — an astrological influence
- Lead pencil — contains graphite, never lead
Greek *atomos*, indivisible, from *a-*, not, plus *temnein*, to cut, through Latin *atomus*.
Why is an atom called uncuttable if it can be split?
The name records an ancient theory that matter is made of indivisible particles. Physics disproved it, but the word stayed.
Who first proposed atoms?
Democritus and his teacher Leucippus, in the fifth century BCE, arguing that matter must be made of indivisible units.