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monatomic

American  
[mon-uh-tom-ik] / ˌmɒn əˈtɒm ɪk /

adjective

Chemistry.

  1. having one atom in the molecule.

  2. containing one replaceable atom or group.

  3. having a valence of one.

monatomic British  
/ ˌmɒnəˈtɒmɪk, ˌmɒnəʊəˈtɒmɪk /

adjective

  1. (of an element) having or consisting of single atoms

    argon is a monatomic gas

  2. (of a compound or molecule) having only one atom or group that can be replaced in a chemical reaction

  3. a less common word for monovalent

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • monatomically adverb

Etymology

Origin of monatomic

First recorded in 1840–50; mon- + atomic

Vocabulary lists containing monatomic

Chemistry - High School

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The ions that we have discussed so far are called monatomic ions, that is, they are ions formed from only one atom.

From Textbooks • Feb. 14, 2019

The oxidation number of a monatomic ion is equal to the ion’s charge.

From Textbooks • Feb. 14, 2019

Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction.

From Textbooks • Feb. 14, 2019

Reinhardt, A. & Doye, J. P. K. Free energy landscapes for homogeneous nucleation of ice for a monatomic water model.

From Nature • Nov. 7, 2017

Its ratio of specific heats has very nearly the ideal value 1.666, appropriate to a monatomic molecule.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2 "Hearing" to "Helmond" by Various

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.