mass number

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Related to mass numbers: Isotopes, atomic number 100, Atomic numbers

number

 [num´ber]
a symbol, as a figure or word, expressive of a certain value or a specified quantity determined by count.
atomic number (Z) a number expressive of the number of protons in an atomic nucleus, or the positive charge of the nucleus expressed in terms of the electronic charge.
Avogadro's number (N) (NA) the number of molecules in one mole of a substance: 6.023 × 1023. Called also Avogadro's constant.
CT number the density assigned to a voxel in a CAT scan on an arbitrary scale on which air has a density −1000; water, 0; and compact bone +1000. See also hounsfield unit.
mass number (A) the number of nucleons (protons plus neutrons) in the atom of a nuclide; generally indicated by a superscript preceding the symbol of a chemical element (e.g., 131I), denoting a specific isotope.
oxidation number a number assigned to each atom in a molecule or ion that represents the number of electrons theoretically gained (positive oxidation numbers) or lost (negative numbers) in converting the atom to the elemental form.

mass num·ber

the mass of the atom of a particular isotope relative to hydrogen-1 (or to 1/12 the mass of carbon 12); generally very close to the whole number represented by the sum of the protons and neutrons in the atomic nucleus of the isotope (indicated in the name or symbol of the isotope, for example, oxygen-16, 16O); not to be confused with the atomic weight of an element, which may include a number of isotopes in their natural proportion.

mass number (A)

the sum of the number of protons and neutrons in the nucleus of an atom or isotope. See also atomic number.

mass number

The number of protons and neutrons in a nuclide (e.g., 14 in 14C).

mass num·ber

(mas nŭmbĕr)
Atomic mass of a particular isotope relative to hydrogen-1 (or to 1/12 the mass of carbon 12); generally very close to the whole number represented by the sum of the protons and neutrons in the atomic nucleus of the isotope (indicated in the name or symbol of the isotope, e.g., oxygen-16, 16O); not to be confused with the atomic weight of an element, which may include a number of isotopes in their natural proportion.

mass number,

n the total number of protons and neutrons within the nucleus of an atom. This number represents the atom's approximate mass.

mass number (A),

n the number of nucleons (protons and neutrons) in the nucleus of an atom.

mass

1. a lump or collection of cohering particles.
2. that characteristic of matter which gives it inertia.

mass-action ratios
the ratio of substrate to product, where the predominance of one, usually the substrate, over the other thermodynamically favors a particular direction for a reaction.
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.
mass medication
(or immunization, or treatment, or prophylaxis, or testing, or screening) application of the procedure to all of the animals in the population, which may be as small as a herd or as large as a national herd. This sort of strategy has been used extensively and for many years in the control of diseases of animals, and has been the principal reason for the dramatic virtual eradication of the major plagues in many countries. The unintelligent extension of the strategy to the control of wastage caused by endemic disease has contributed most to the problem of residues of antibacterial drugs in the human food chain. See also mass medication.
mass number
the number used to express the mass of a nucleus, being the total number of nucleons, protons and neutrons in the nucleus of an atom or nuclide; symbol A.
mass reflex
reflex actions by all the body parts controlled by the part of the spinal cord which has been injured.
thalamic intermediate mass

number

a symbol, as a figure or word, expressive of a certain value or a specified quantity determined by count.

atomic number
a number expressive of the number of protons in an atomic nucleus, or the positive charge of the nucleus expressed in terms of the electronic charge; symbol A.
Avogadro's number
see avogadro's number.
mass number
see mass number.
Reynold's number
References in periodicals archive ?
Each of these individual populations had undergone two cycles of selection for low gall and egg mass numbers in response to its specific nematodes before intercrossing selected individuals as one population.
Where M is the higher mass number of the two peaks and [DELTA] M is the difference between the two mass numbers.
But with 150,000 people dying every year from global warming, Greenpeace feels we're in a climate crisis - and if humanity is to solve the problem we need radical action, the kind of action that can only be forced through by mass numbers of people taking action to display the strength of feeling out there.
One of the first results of this work is currently underway and involves a direct mail campaign which, while reaching mass numbers, is at the same time highly targeted.
Furthermore, our niche products have no need to match the mass numbers of those media.
While METI aims to require mail-order businesses sending e-mail advertisements to protect consumers, the LDP bill aims to prevent such ads, often sent in mass numbers, from causing disruption to communication lines, he said.
These two points raise the complex issues of locations and critical mass numbers.
The Gungans, in addition to dying in mass numbers for the cause, are the comic relief.
Instead, broadcasters are simply trying to get out the message that they have the ability to reach large numbers of people even when targeting certain groups, unlike cablers or nichecasters like the WB which, while able to bring in small concentrations of certain viewers, are rarely able to deliver mass numbers of any kind.
There's even a value in not trying to print mass numbers of this, but to keep the thing targeted," he said.
The first is a simple problem of supply and demand: If mass numbers of people are underemployed or unemployed, who's going to buy the flood of products and services being churned out?
We tried on umpteen occasions, when aircraft were taking off in mass numbers," he says.