Atomic Weight (Noun)
Meaning
(chemistry) the mass of an atom of a chemical element expressed in atomic mass units.
Classification
Nouns denoting attributes of people and objects.
Examples
- The atomic weight of oxygen is 15.9994 u, or unified atomic mass units, which is a weighted average of its naturally occurring isotopes.
- Carbon-12 is the standard for the atomic weight scale, with a value of exactly 12 u.
- The atomic weight of chlorine is 35.453 u, which is a weighted average of its two major isotopes.
- In chemistry, the atomic weight of an element is essential for calculating the molar mass of compounds.
- The International Committee on Weights and Measures defines the atomic weight of an element as the average mass of a representative sample of naturally occurring atoms of the element.