Avogadro Constant
The Avogadro constant NA is determined as the ratio of the mass of one mole of electrons to the mass of a single electron: The mass of one mole of electrons is the "relative atomic mass" of an electron Ar(e), which can be measured in a Penning trap (ur = 4.2×10−10), multiplied by the molar mass constant Mu, which is defined as 0.001 kg/mol.
The dependence of the Avogadro constant on the Planck constant (r2 > 0.999) also holds for the physical constants which are related to amount of substance, such as the atomic mass constant. The uncertainty in the value of the Planck constant limits the knowledge of the masses of atoms and subatomic particles when expressed in SI units. It is possible to measure the masses more precisely in atomic mass units, but not to convert them more precisely into kilograms.
Read more about this topic: Planck Constant, Dependent Physical Constants
Other articles related to "avogadro constant, avogadro, constant":
... Another Avogadro constant-based approach, known as the Avogadro project, would define and delineate the kilogram as a softball-size (93.6 mm diameter) sphere of silicon atoms ... Experiments are being performed on the Avogadro Project’s silicon spheres to determine whether their masses are most stable when stored in a vacuum, a partial vacuum, or ambient pressure ... All silicon-based approaches would fix the Avogadro constant but vary in the details of the definition of the kilogram ...
... The International Avogadro Coordination (IAC), often simply called the "Avogadro project", is a collaboration begun in the early 1990s between various national metrology institutes to measure the Avogadro constant by ... kilogram in terms of a universal physical constant, rather than the International Prototype Kilogram, and complements the measurements of the Planck ... current definitions of the International System of Units (SI), a measurement of the Avogadro constant is an indirect measurement of the Planck constant The ...
... The number of atoms in a mole, a quantity known as the Avogadro constant, is experimentally determined, and the current best estimate of its value is ... This new definition of the kilogram proposed to fix the Avogadro constant at precisely 6.02214X×10^23 with the kilogram being defined as “the mass equal to that of 1000⁄12 · 6.02214X×10^23 ... By fixing the Avogadro constant, the practical effect of this proposal would be that the uncertainty in the mass of a 12C atom—and the magnitude of the kilogram—could ...
... If the Avogadro constant NA and the Faraday constant F are independently known, the value of the elementary charge can be deduced, using the formula (In other ...
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