Occurring as single atoms: Helium is a monatomic gas. (adjective)
Having one replaceable atom or radical.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "monatomic" in a sentence
"Ionization was also observed in monatomic inert gases, which proves that the unit of electric charge is a constituent of the atom that is liberated from it by ionization."
"Due to their antisocial and imperturbable nature they occur in ChemicalData as only their monatomic selves."
"These atoms still try to reshape even after forming a molecule but find their efforts opposed by the new covalent bond, the covalent bond gets broken by this reshaping force when the molecule moves to a spatial position where the Casimir force changes sufficiently that the reshaping force disassociates the molecule restoring monatomic energy levels."