noun

atom

atom

A water molecule has two hydrogen atoms.

A water molecule has two hydrogen atoms.

He didn't have an atom of sense.

He didn't have an atom of sense.

an atom of (sth.) a basic unit of a chemical element A molecule of water consists of two atoms of hydrogen.

Synonyms: particle, element; Antonyms: whole, compound

From Greek 'atomos', meaning 'uncut, indivisible', from 'a-' (not) + 'tomos' (a cutting).

Remember its origin 'a-tom' (not-cut). It was once thought to be the smallest thing that could not be divided further.

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