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

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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