Definitions for "Atomic theory"
the theory that all matter is made up of fundamental particles called atoms. the concept of an atom as being composed of subatomic particles. See also: Briefing Room
A model that offers a logical explanation for the law of multiple proportions and the law of constant composition by stating that all elements are composed of atoms, all atoms of a given element are identical, but the atoms of one element differ from the atoms of any other element; that atoms of different elements can combine to form compounds and a chemical reaction involves a change not in the atoms themselves, but in the way atoms are combined to form compounds.
a theory of the structure of the atom
a model developed to explain the properties and behaviors of atoms