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

In 2019, he registered a trademark for an esoteric video game called “Bohrdom,” a “hybrid of a bullet hell and a racing game” based on atomic theory, in which electrons and protons compete.

From Los Angeles Times • May 3, 2026

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

Note that the atomism alluded to here is different from what is referred to as atomic theory.

From Textbooks • Jun. 15, 2022

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

Thus, the atomic theory required that the universe be filled with emptiness—an infinite void.

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