atomic theory

American  

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.

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atomic theory British  

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

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Etymology

Origin of atomic theory

First recorded in 1840–50

Example Sentences

Manchester had been steadily attracting scientific prestige after John Dalton pioneered studies in atomic theory and colour blindness, while fellow student James Joule became a household name after his work in energy conservation.

From BBC • Jul. 29, 2023

These fluids mix well together in outer portions of such a planet’s deep interior, but in the depths, the tenets of atomic theory predict they will “unmix” like water and oil.

From Scientific American • Jul. 21, 2021

Does the following chemical change represented by these symbols violate any of the ideas of Dalton’s atomic theory?

From Textbooks • Feb. 14, 2019

This field drew on research in physics and chemistry that extended back to the early 1900s and the development of modern atomic theory.

From Slate • Sep. 27, 2016

Another philosophy vied with the atomic theory, and instead of posing such bizarre concepts as the infinite vacuum, it turned the universe into a cozy nutshell.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife