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The Avogadro constant, commonly denoted N A [1] or L, [2] is an SI defining constant with an exact value of 6.022 140 76 × 10 23 mol −1 (reciprocal moles). [3] [4] It is this defined number of constituent particles (usually molecules, atoms, ions, or ion pairs—in general, entities) per mole and used as a normalization factor in relating the amount of substance, n(X), in a sample of a ...
This number is the fixed numerical value of the Avogadro constant, N A, when expressed in the unit mol −1 and is called the Avogadro number. The amount of substance, symbol n , of a system is a measure of the number of specified elementary entities.
Historically, N 0 approximates the number of nucleons (protons or neutrons) in one gram of ordinary matter. The Avogadro constant (symbol N A = N 0 /mol) has numerical multiplier given by the Avogadro number with the unit reciprocal mole (mol −1). [2] The ratio n = N/N A is a measure of the amount of substance (with the unit mole). [2] [3] [4]
The magnitude of the electrical charge of one mole of elementary charges (approximately 6.022 × 10 23, the Avogadro number) is known as a faraday unit of charge (closely related to the Faraday constant). One faraday equals 9.648 533 212... × 10 4 coulombs. [5]
The mole is dimensionless in UCUM, since it can be defined in terms of the Avogadro number, The radian is a distinct base unit for plane angle , to distinguish angular velocity from rotational frequency and to distinguish the radian from the steradian for solid angles .
This number is the fixed numerical value of the Avogadro constant, N A, when expressed in the unit mol −1 and is called the Avogadro number. [7] [48] The amount of substance, symbol n, of a system is a measure of the number of specified elementary entities. An elementary entity may be an atom, a molecule, an ion, an electron, any other ...
The interest stems from that accurate measurements of the unit cell volume, atomic weight and mass density of a pure crystalline solid provide a direct determination of the Avogadro constant. [3] The CODATA recommended value for the molar volume of silicon is 1.205 883 199 (60) × 10 −5 m 3 ⋅mol −1, with a relative standard uncertainty of ...
Charge carrier density, also known as carrier concentration, denotes the number of charge carriers per volume. In SI units, it is measured in m −3. As with any density, in principle it can depend on position. However, usually carrier concentration is given as a single number, and represents the average carrier density over the whole material.