Avogadro number

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Related to Avogadro constant: atomic mass unit, gas constant, Pv=nrt

A·vo·gad·ro num·ber (Λ, NA),

the number of molecules in 1 gram-molecular weight (1 mol) of any compound; defined as the number of atoms in 0.0120 kg of pure carbon-12; equivalent to 6.0221367 × 1023.
Synonym(s): Avogadro constant
[Amadeo Avogadro]
Farlex Partner Medical Dictionary © Farlex 2012

A·vo·gad·ro num·ber

(NA, λ) (ah-vō-gahd'rō nŭm'bĕr)
The number of molecules in 1 gram-molecular weight (1 mol) of any compound; defined as the number of atoms in 0.0120 kg of pure carbon 12; equivalent to 6.0221367 × 1023.
Synonym(s): Avogadro constant.
[Amadeo Avogadro]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Avogadro number

The number of molecules, 6.0221367×1023, in one gram molecular weight of a compound.
Medical Dictionary, © 2009 Farlex and Partners


Amadeo, Italian physicist, 1776-1856.
Avogadro constant - Synonym(s): Avogadro number
Avogadro hypothesis - Synonym(s): Avogadro law
Avogadro law - equal volumes of gases contain equal numbers of molecules, the conditions of pressure and temperature being the same. Synonym(s): Ampère postulate; Avogadro hypothesis; Avogadro postulate
Avogadro number - the number of molecules in one gram-molecular weight (1 mol) of any compound. Synonym(s): Avogadro constant
Avogadro postulate - Synonym(s): Avogadro law
Medical Eponyms © Farlex 2012
References in periodicals archive ?
[29] Becker P, Bettin H, Danzebrink HU, Glaser M, Kuetgens U, Nicolaus A, Schiel D, Bievre PD, Valkiers S, Taylor P (2003) Determination of the Avogadro constant via the silicon route.
[31] Fujii K, Waseda A, Kuramoto N, Mizushima S, Becker P, Bettin H, Nicolaus A, Kuetgens U, Valkiers S, Taylor P, Paul DB, Mana G, Massa E, Matyi R, Kessler EG, Jr., Hanke M (2005) Present State of the avogadro constant determination from silicon Crystals with natural isotopic compositions.
These redefinitions will depend on fixing other constants, including the Avogadro constant. Making all of these changes at once will limit the number of times textbooks must be changed, Stock says.
Caption: Newly calculated value of the Avogadro constant
The mole, symbol mol, is the unit of amount of substance of a specified elementary entity, which may be an atom, molecule, ion, electron, any other particle or a specified group of such particles; its magnitude is set by fixing the numerical value of the Avogadro constant to be equal to exactly 6.022 141 ...
But the problem now is that not everyone agrees on the true number for the Avogadro constant. American and British teams have tried measuring the constant another way, by balancing gravity's force on a mass with the electrical forces needed to suspend it in midair, but repeated trials gave inconsistent measures of the constant.
As long as the Avogadro constant stays constant, it will be useful for defining the kilogram.
X-ray spacings in crystals, another great NBS specialty, and density of crystals of known chemical and isotopic composition yield the Avogadro constant by the XRCD (X-Ray Crystal Density) method.
Equivalent procedures were used in the x-ray spacing measurements for silicon crystals for the XRCD method deriving the Avogadro constant (17).
These include the Josephson constant, the charge and mass of the electron, and the Avogadro constant [2].