Akademik

1. a theory of the structure of the atom

2. (chemistry) any theory in which all matter is composed of tiny discrete finite indivisible indestructible particles

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the ancient Greek philosophers Democritus and Epicurus held atomic theories of the universe

aˌtomic ˈtheory [atomic theory] noun (chemistry, physics)

the theory that all elements are made up of small ↑particles called atoms which are made up of a central ↑nucleus surrounded by moving ↑electrons