atomic weight

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atomic weight

n.
The average mass of an atom of an element, usually expressed relative to the mass of carbon 12, which is assigned 12 atomic mass units.

atomic weight

n
(Chemistry) the former name for relative atomic massAbbreviation: at wt

atom′ic weight′


n.
the average weight of an atom of an element, based on 1/12 the weight of the carbon-12 atom. Abbr.: at. wt.

atomic weight

The average mass of a chemical element, 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. Compare atomic mass.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.atomic weight - (chemistry) the mass of an atom of a chemical element expressed in atomic mass unitsatomic weight - (chemistry) the mass of an atom of a chemical element expressed in atomic mass units
mass - the property of a body that causes it to have weight in a gravitational field
combining weight, eq, equivalent weight, equivalent - the atomic weight of an element that has the same combining capacity as a given weight of another element; the standard is 8 for oxygen
meq, milliequivalent - one-thousandth of an equivalent
chemical science, chemistry - the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions
Translations
References in periodicals archive ?
Every two years, the International Union of Pure and Applied Chemistry (IUPAC) Commission on Isotopic Abundances and Atomic Weights meets to discuss how best to communicate the latest data on various elements.
Table 1: Continued fraction representations of the 20 most accurately determined atomic weights (Helium and the set of 19 mononuclidic non-radioactive elements), x = 1.
This machine knows the atomic weights of millions of microscopic particles and can recognise each one.
Prout's name is associated with the two hypotheses of integral atomic weights and the unity of matter, i.
The relation between vapor density and molecular weight, the significance of the valence in electrolysis, and the influence of physical considerations on the choice of comparable atomic weights, whose arrangement in Lothar Meyer's table conveys to us one of the most important laws of nature, are some topics of mutual interest.
IUPAC is recognized as the world authority on chemical nomenclature, terminology, standardized methods for measurement, atomic weights and many other critically evaluated data.
A note by Mendeleev, in March of 1869, was published and sent in Russian and French to scientists, titled "Experience of Systems of Elements Founded on Their Atomic Weights and Chemical Similarity" (with "atomic weight" to be understood as "atomic mass" here and in the future).
Just as the weight listed on your driver's license doesn't necessarily reflect your actual poundage, the official atomic weights of most chemical elements are actually more like ballpark estimates than precise constants.
Taylor, The Atomic Weights of the Elements, Review 2000, Pure Appl.
Appendix 6: Atomic Weights, Concentrations, Exponents, Greek and Roman Letters, Ions, Measurements, Molecular Weights, Prefixes, Valences, Units, and Solutions
John Dalton (top), an English schoolteacher, compiles the first table of atomic weights for various elements, using units where the atomic weight of hydrogen was equal to 1.
If chemical industry was to operate internationally, it was critically important to establish standards and values for chemical nomenclature, units, atomic weights, etc.