Fundamental metric system constant defined as the number of particles per mole
Avogadro constant
Amedeo Avogadro, the constant's namesake
Common symbols
NA, L
SI unit
mol−1
Exact value
reciprocal mole
6.02214076×1023
The Avogadro constant, commonly denoted NA[1] or L,[2] is an SI defining constant with an exact value of 6.02214076×1023 mol−1 (reciprocal moles).[3][4] It is defined as the number of constituent particles (usually molecules, atoms, or ions) per mole (SI unit) and used as a normalization factor in the amount of substance in a sample. The constant is named after the physicist and chemist Amedeo Avogadro (1776–1856).
The Avogadro constant NA is also the factor that converts the average mass of one particle, in grams, to the molar mass of the substance, in grams per mole (g/mol).[5]
The constant NA also relates the molar volume (the volume per mole) of a substance to the average volume nominally occupied by one of its particles, when both are expressed in the same units of volume. For example, since the molar volume of water in ordinary conditions is about 18 mL/mol, the volume occupied by one molecule of water is about 18/(6.022×1023) mL, or about 0.030 nm3 (cubic nanometres). For a crystalline substance, N0 relates the volume of a crystal with one mole worth of repeating unit cells, to the volume of a single cell (both in the same units).
In the SI dimensional analysis of measurement units, the dimension of the Avogadro constant is the reciprocal of amount of substance, denoted N−1. The Avogadro number, sometimes denoted N0,[6][7] is the numeric value of the Avogadro constant (i.e., without a unit), namely the dimensionless number 6.02214076×1023.[1][8]
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Newell, David B.; Tiesinga, Eite (2019). The International System of Units (SI). NIST Special Publication 330. Gaithersburg, Maryland: National Institute of Standards and Technology. doi:10.6028/nist.sp.330-2019. S2CID 242934226.
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The Avogadroconstant, commonly denoted NA or L, is an SI defining constant with an exact value of 6.02214076×1023 mol−1 (reciprocal moles). It is defined...
is known as the Avogadroconstant. This constant is denoted NA, and is one of the seven defining constants of the SI. Amedeo Avogadro was born in Turin...
to amount of substance. The gas constant R is defined as the Avogadroconstant NA multiplied by the Boltzmann constant k (or kB): R = N A k {\displaystyle...
units, for the Planck constant (h), the elementary electric charge (e), the Boltzmann constant (kB), and the Avogadroconstant (NA), respectively. The...
alternative approaches included: One Avogadroconstant-based approach, known as the International Avogadro Coordination's Avogadro project, would define and delineate...
temperature to the dimension of energy per degree of freedom, and the Avogadroconstant N A {\displaystyle N_{\text{A}}} , which gives the correspondence...
units, the Faraday constant has an exactly-defined value, the product of the elementary charge (e, in coulombs) and the Avogadroconstant (NA, in reciprocal...
of Jerusalem Amedeo Avogadro (1776–1856), chemist. Named after him are: AvogadroconstantAvogadro's law, an ideal gas law Avogadro project, a project...
1901 and (through the Faraday constant) at order-of-magnitude accuracy by Johann Loschmidt's measurement of the Avogadro number in 1865. In some natural...
Value: Avogadroconstant". The NIST Reference on Constants, Units, and Uncertainty. NIST. May 2024. Retrieved 2024-05-18. "reduced Planck constant". The...
(n = N/NA) between the number of elementary entities (N) and the Avogadroconstant (NA). The entities are usually molecules, atoms, or ions of a specified...
fundamental constants, namely the Planck constant (h), the elementary charge (e), the Boltzmann constant (k), and the Avogadroconstant (NA). This approach...
constant (8.31446261815324 J⋅K−1⋅mol−1). Introducing the Boltzmann constant as the gas constant per molecule k = R/NA (being NA the Avogadroconstant)...
of molecules in 1865. The term "Loschmidt constant" is also sometimes used to refer to the Avogadroconstant, particularly in German texts. By ideal gas...
V_{\rm {m}}={{N_{\rm {A}}V_{\rm {cell}}} \over {Z}}} where NA is the Avogadroconstant and Z is the number of formula units in the unit cell. The result...
either MDY or YMD date formats. The time and date are derived from the Avogadroconstant, which is approximately 6.02×1023, defining the number of particles...
using an upper-case L. In chemistry, L is used as a symbol for the Avogadroconstant. This article contains special characters. Without proper rendering...
litres) of the solution, and N A {\displaystyle N_{\text{A}}} is the Avogadroconstant, since 2019 defined as exactly 6.02214076×1023 mol−1. The ratio N...
frequency of caesium ΔνCs, the Planck constant h, the elementary charge e, the Boltzmann constant k, the Avogadroconstant NA, and the luminous efficacy Kcd...
constant and the Rydberg constant, as detailed above. The electron mass is used to calculate[citation needed] the Avogadroconstant NA: N A = M u A r ( e...
gas constant in units of J mol−1K−1. The unit of r(T) can be converted to mol⋅L−1⋅s−1, after divided by (1000×NA), where NA is the Avogadroconstant. For...
v=VN_{\text{A}}/N} is molar volume, N A {\displaystyle N_{\text{A}}} is the Avogadroconstant, V {\displaystyle V} is the volume, and N {\displaystyle N} is the...
volume of a single atom or molecule, it is necessary to divide by the Avogadroconstant NA. The molar van der Waals volume should not be confused with the...
{\displaystyle M_{\rm {u}}} is the molar mass constant, N A {\displaystyle N_{\rm {A}}} is the Avogadroconstant, and M ( 12 C ) {\displaystyle M(^{12}\mathrm...
the latter is obtained by dividing the molar mass of the gas by the Avogadroconstant. The first part of Einstein's argument was to determine how far a...
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