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.

---

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

---

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

First published in 1807, many of Dalton’s hypotheses about the microscopic features of matter are still valid in modern 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

This was a shocking conclusion, but the indivisible kernels of matter in atomic theory got around the problem of Zeno’s paradoxes.

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