atomic weight
the average weight of an atom of an element, formerly based on the weight of one hydrogen atom taken as a unit or on 1/16 (0.0625) the weight of an oxygen atom, but after 1961 based on 1/12 the weight of the carbon-12 atom. Abbreviation: at. wt.
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Origin of atomic weight
1Words Nearby atomic weight
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
How to use atomic weight in a sentence
She had an atomic weight upon which you could depend as upon any other known quantity.
Unveiling a Parallel | Alice Ilgenfritz Jones and Ella MarchantThe numbers denote the atomic weight of the atom, which is the total number of protons and neutrons in its nucleus.
The Atomic Fingerprint | Bernard KeischSimilarly 56 is the atomic weight of iron, and 32 the atomic weight of sulphur.
A Textbook of Assaying: For the Use of Those Connected with Mines. | Cornelius Beringer and John Jacob BeringerIts atomic weight would be about 68; that of gallium is 699.
The atomic weight of any particular element is the weight of its atom compared with the weight of an atom of hydrogen.
A Textbook of Assaying: For the Use of Those Connected with Mines. | Cornelius Beringer and John Jacob Beringer
British Dictionary definitions for atomic weight
the former name for relative atomic mass Abbreviation: at wt
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 weight
The mass of an atom expressed in atomic mass units. The atomic weight of an element having more than one principal isotope is calculated both from the atomic masses of the isotopes and from the relative abundance of each isotope in nature. For example, the atomic weight of the element chlorine is 35.453, determined by averaging the atomic masses and relative abundances of its two main naturally occurring isotopes, which have atomic masses of about 35 and 37. Also called relative atomic mass Compare atomic mass. See also mass number.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for atomic weight
The mass of a given atom, measured on a scale in which the hydrogen atom has the weight of one. Because most of the mass in an atom is in the nucleus, and each proton and neutron has an atomic weight near one, the atomic weight is very nearly equal to the number of protons and neutrons in the nucleus. (See atomic number.)
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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