atomic mass

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1. a lump or collection of cohering particles.
2. that characteristic of matter that gives it inertia. Symbol m.
atomic mass atomic weight; see also atomic mass unit.
inner cell mass an internal cluster of cells at the embryonic pole of the blastocyst which develops into the body of the embryo.
lean body mass that part of the body including all its components except neutral storage lipid; in essence, the fat-free mass of the body.
relative molecular mass technically preferable term for molecular weight.

atomic mass (A)

the average mass, relative to an atom of carbon, of an atom of an element based on the natural isotopic mix of that element. Also called atomic weight. See also atomic mass unit.

a·tom·ic mass

(ă-tomik mas)
Total number of protons, neutrons, and electrons in an atom.
References in periodicals archive ?
For SRM 1649a, however, where only about 40 % of the carbon, on average, is biogenic, there is a wealth of information contained in the varying contributions of fossil and biomass sources to different chemical species, as well as the aforementioned opportunity to use isotopic mass balance for an extra measure of quality control.
Application of isotopic mass balance equations to the ucm that was isolated with the benzo(ghi)perylene peak gave a biomass carbon contribution of [approximately equal to] = 15%.
The quest for isotopic mass balance, and complete isotopic speciation, generates challenging questions when that balance has not been achieved.