atom · noun C /ˈæt̬.əm/Full view
B2 the smallest unit that an element can be divided into
Dictionary example:

A molecule of carbon dioxide (CO2) has one carbon atom and two oxygen atoms.

Learner example:

Anyway, the manager of that cent[er] called me in order to inform me that I would [be doing] research on nuclear power and atoms. (First Certificate in English; B2; Greek)

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