atomic theory

noun

Definition of atomic theory

1 : a theory of the nature of matter: all material substances are composed of minute particles or atoms of a comparatively small number of kinds and all the atoms of the same kind are uniform in size, weight, and other properties
2 : any of several theories of the structure of the atom especially : one based on experimentation and theoretical considerations holding that the atom is composed essentially of a small positively charged comparatively heavy nucleus surrounded by a comparatively large arrangement of electrons

Examples of atomic theory in a Sentence

Recent Examples on the Web

But Rovelli says that the degree of confirmation of atomic theory shouldn’t even be measured in the same units as that of string theory. Quanta Magazine, "A Fight for the Soul of Science," 16 Dec. 2015 String theory is not, say, 10 percent as confirmed as atomic theory; the two have different statuses entirely. Quanta Magazine, "A Fight for the Soul of Science," 16 Dec. 2015

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'atomic theory.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of atomic theory

1738, in the meaning defined at sense 1

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The first known use of atomic theory was in 1738

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More Definitions for atomic theory

atomic theory

noun

Medical Definition of atomic theory

1 : a theory of the nature of matter: all material substances are composed of minute particles or atoms of a comparatively small number of kinds and all the atoms of the same kind are uniform in size, weight, and other properties

called also atomic hypothesis

2 : any of several theories of the structure of the atom especially : one based on experimentation and theoretical considerations holding that the atom is composed essentially of a small positively charged comparatively heavy nucleus surrounded by a comparatively large arrangement of electrons

More from Merriam-Webster on atomic theory

Britannica.com: Encyclopedia article about atomic theory

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