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

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.
References in periodicals archive ?
Now it is possible to calculate the number of neutrons in the void volume (excluding the first envelope, which is the transition boundary structure, where the nuclear and charge density fall sharply down) and then the mass number. For lead the outer radius of the second envelope is 9.66 - 2[r.sub.n] = 7.98 fm, its volume is 2130 [fm.sup.3].
Because program officials want the work done by the core members, and not by the four associates working with them, the capacity to produce quickly in mass numbers remains low, Ghareeb said.
"People are fleeing in mass numbers and coming to Ormoc, where they stand in line all day to get on a ferry only to be turned away," he said.
It''s about time we united and fought back in mass numbers.
I do acknowledge that he has given good scores in many movies in his limited range but he has failed to be convincing when he has gone in for mass numbers. Nearly a decade ago, he had done a new version of Vande Matram.
We won't get mass numbers straight away, but we are looking at a long-term commitment to develop the market by spending time meeting the frontline travel agents who can help us understand the market.
"The banks lost a lot of money when the crisis occurred because never before have there been mass numbers -- thousands of expatriates losing their jobs in a short period of time," Scotto said.
The present system of education is designed to kill creativity and produce mass numbers of 'educated' who are desperately trying and vying for every job in sight with the result that organisations are full of disengaged misfits whose commitment and contribution is mediocre at best.
Invoking the names of famous people, who function as universal shorthand for various character traits and fragments of cultural narrative, provides a similarly direct route to mass numbers of brains.
Is it because we don't voice our disagreement strongly enough or in mass numbers? Do we subscribe to the victim mentality?
Then, this nucleus splits into two complementary light and heavy fragments having AL and [A.sub.H] as mass numbers, and [E.sub.L] and [E.sub.H] as kinetic energies, respectively.