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atomic mass

[ uh-tom-ik mas ]
/ əˈtɒm ɪk ˈmæs /
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See synonyms for atomic mass on Thesaurus.com
noun Chemistry.
the mass of an isotope of an element measured in units formerly based on the mass of one hydrogen atom taken as a unit or on 1/16 (0.0625) the mass of one oxygen atom, but after 1961 based on 1/12 (0.0833) the mass of the carbon-12 atom.

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Origin of atomic mass

First recorded in 1895–1900

Words nearby atomic mass

Atomic Energy Commission, atomic force microscope, atomic heat, atomic hydrogen, atomicity, atomic mass, atomic mass unit, atomic number, atomic pile, atomic power, atomics
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Words related to atomic mass

atomic number, atomic volume, atomic weight, nucleon number

How to use atomic mass in a sentence

  • What is specially of interest is that the indicated atomic mass of each of the constituents is a whole number.

    Alchemy: Ancient and Modern|H. Stanley Redgrove

  • The best evidence that these particles are of atomic mass is furnished by their deflection in electric and magnetic fields.

    A Brief Account of Radio-activity|Francis Preston Venable

British Dictionary definitions for atomic mass

atomic mass
noun chem
the mass of an isotope of an element in atomic mass units
short for relative atomic mass See atomic weight
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

Scientific definitions for atomic mass

atomic mass
The mass of a given atom or molecule, expressed in atomic mass units. Compare atomic weight. See also mass number.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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