atomic mass

Also found in: Dictionary, Thesaurus, Legal, Acronyms, Encyclopedia, Wikipedia.
Related to atomic mass: atomic weight, relative atomic mass, Atomic mass number


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 ?
Take the square root of atomic mass of rhodium (X = = Y = 10.
Mass number of an isotope is equal to the numerical value of its mass, measured in atomic mass units (a.
So really it was just transferring the concepts of a fluorescent assay into the atomic mass spectrometry world, where you get the advantages of high-resolution detection, quantitative assay, enormous dynamic range--all the kinds of things you want in an analytical platform.
We must conclude that mass, represented here by the additional atomic mass of neutrons, does not affect backscattering of electrons under microprobe conditions.
This law is due to the fact that the element content Y when estimated in relation to 1 gram-atom, in any chemical combination with molecular mass X, may be described by the adduced equations for the positive branches of the rectangular hyperbolas of the type Y = K/X (where Y [less than or equal to] 1, K [less than or equal to] X), arranged in the order of increasing nuclear charge, and having the common virtual axis with their peaks tending to the state Y =1 or K =X as they become further removed from the origin of coordinates, reaching a maximum atomic mass designating the last element.
This element, which can bind to form ozone, has an atomic mass of 15.
The inertial mass of an given atomic nucleus is the atomic mass units it possesses, but this atomic mass is not exactly equivalent to the total of neutrons and protons.
The Nuclear Solutions technology is an electron accelerator-based photodisintegration process that reduces the atomic mass of radioactive materials, thereby rendering them non-radioactive or radioactive with a short half-life.
Have a minimum scanning mass range of 10-1000 Atomic Mass Unit (AMU).
By doing some simple math we can see that the total mass of the silicone repeating unit is 74 atomic mass units.
The special characteristics of xenon -- it exists naturally in nine different isotopes, ranging in atomic mass from 124 (with 70 neutrons per atom) to 136 (with 82 neutrons per atom) -- allows us to learn more about the process by which the layers of atmosphere were stripped off of Mars than using measurements of other gases.