atomic theory

noun

1. Physics, Chemistry.,  any of several theories describing the structure, behavior, and other properties of the atom and its component parts.

2. Philosophy.,  atomism.

atomic theory

noun

1. any theory in which matter is regarded as consisting of atoms, esp that proposed by John Dalton postulating that elements are composed of atoms that can combine in definite proportions to form compounds

2. the current concept of the atom as an entity with a definite structure See atomic structure

Word History and Origins

Origin of atomic theory¹

First recorded in 1840–50