atomic number

(redirected from Atomic numbers)
Also found in: Dictionary, Thesaurus, Encyclopedia.

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.

a·tom·ic num·ber (Z),

the number of protons in the nucleus of an atom; it indicates the position of the element in the periodic system.

atomic number

the number of protons in the nucleus of an atom of a particular element. In a neutral atom, the atomic number equals the number of electrons. See also atom, electron, proton.

a·tom·ic num·ber

(Z) (ă-tom'ik nŭm'bĕr)
The number of protons in the nucleus of an atom; it indicates the position of the element in the periodic system.

atomic number,

n the number of protons within an atom's nucleus.

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 ?
Background intensities measured in previous analyses or derived from modelling calculations can be utilised, but should be scaled according to mean atomic number to allow for the effect this has on continuum intensity.
A nuclide is that version of an atom defined by its mass number (A = Z + N), its atomic number (Z) and a power condition of its nucleus.
The other method is to plot a series of measurements of the property versus calculated hypothetical average atomic numbers and observe the smoothness of fit to a simple polynomial or exponential curve.
663243 and an atomic number (the nuclear charge) of 155.
In that article, Dmitri described a systematic naming convention for the chemical elements with atomic numbers greater than 100.
A second positive aspect of low voltage microanalysis is the dependence upon beam energy of the matrix or inter-element effects, atomic number (scattering and stopping power), absorption, and secondary x-ray fluorescence, which must be considered in quantitative analysis.
However, as the atomic numbers of I and Nb are greater than those of B and Fe, this set is less economical, as well as requiring 36 elementary operations.
They predict a stronger deformation and even greater stability for a nucleus with atomic number 108 and mass number 270.
The list below contains 109 elements, with atomic numbers from 1 to 109.
Because atoms with higher atomic numbers block more neutrinos, researchers may eventually use DUMAND and other detectors to help decipher what types of minerals and elements make up Earth's mantle and core.
This is a range of relatively stable nuclei with atomic numbers just above 110.
A persistent prediction of nuclear physics is that certain "superheavy" element--with atomic numbers well above the 109 now known--should be able to form and last long enough to be detected.