number (redirected from numbers)

number /num·ber/ (num´ber) 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  (Z ) a number expressive of the number of protons in an atomic nucleus.

Avogadro's number  (N ) (N A) the number of molecules in one mole of a substance: 6.023 × 1023.

mass number  (A ) the number expressive of the mass of a nucleus, being the total number of protons and neutrons in the nucleus of an atom or nuclide.

oxidation number  a number assigned to each atom in a molecule or ion that represents the number of electrons theoretically lost (negative numbers) or gained (positive numbers) in converting the atom to the elemental form (which has an oxidation number of zero). The sum of the oxidation numbers for all atoms in a neutral compound is zero; for polyatomic ions, it is equal to the ionic charge.

tooth number  a number assigned for each of the permanent teeth in consecutive order, with 1 for the upper right third molar and 17 for the lower left third molar, and proceeding around each jaw.

turnover number  the number of molecules of substrate acted upon by one molecule of enzyme per minute.

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num·ber (nmbr)

n.

1. A symbol expressive of a certain value or of a specific quantity determined by count.

2. The place of any unit in a series.

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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.