- Physics, Chemistry. any of several theories describing the structure, behavior, and other properties of the atom and its component parts.
- Philosophy. atomism(def 1).
Origin of atomic theory
First recorded in 1840–50
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- 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
- the current concept of the atom as an entity with a definite structureSee atomic structure
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012