atomic number

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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 ?
The effect of background curvature is more likely to be significant for samples of high mean atomic number, since the continuum intensity is then greatest, and a given degree of curvature has a greater effect in terms of elemental concentration.
Which two chemical elements have their atomic numbers equal to exactly half their calculated sums?
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.
Finally, I had to ask him to name the elements with atomic numbers lower than 20.
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.
Using such a strategy, researchers have synthesized more than two dozen elements having higher atomic numbers than that of uranium, which has 92 protons in its nucleus.
Linus Pauling (see 1931) had pointed out that the inert gas atoms grew less inert as their atomic number increased, so that those with higher atomic numbers might be induced to form a bond with fluorine, which was the most active of all elements and the most apt to snatch an electron from unlikely places.
Elements with atomic numbers 1 to 92 are the naturally occurring elements.
Those with higher atomic numbers merit the title "transuranium" and are created by scientists using particle accelerators.
Their atomic numbers are: H(1), He(2), Li(3), Be(4), B(5), C(6), N(7), O(8), F(9), Ne(10), Na(11), Mg(12), Al(13), Si(14), P(15), S(16), Cl(17), Ar(18), K(19), Ca(20), Sc(21), Ti(22), V(23), Cr(24), Mn(25), Fe(26).
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.