Avogadro's number

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) (N_A) 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.

Avogadro's number (NA)

the number of atoms in exactly 12 g of the isotope of carbon ¹²C, or 6.02 × 10²³. One mole of any monoatomic element contains this number of atoms and one mole of any polyatomic element or molecule contains this number of molecules.

Avogadro's number,

n.pr the number of molecules that exist in one mole: 6.0225 × 10²³.

number

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

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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

see reynold's number.