A variation on a 12 C-based definition proposes to define the Avogadro constant as being precisely 84, 446, 889 3 ( H " ) atoms.
12.
With this recognition, the Avogadro constant was no longer a pure number, but had a unit of measurement, the reciprocal mole ( mol " 1 ).
13.
In honor of the unit, some chemists celebrate October 23, which is a reference to the 10 23 scale of the Avogadro constant, as " Mole Day ".
14.
Avogadro constant will tell you how many ( * many, many, many *, a really huge number ) atoms you have in a sample of a given weight.
15.
The accuracy of the measured value of the Avogadro constant is currently limited by the uncertainty in the value of the Planck constant a measure relating the energy of photons to their frequency.
16.
Such methods require a knowledge of the Avogadro constant, which fixes the proportionality between atomic mass and macroscopic mass but, with a defined value of the Planck constant, " N"
17.
These can range from mathematic equations ( for example the Avogadro constant is constantly used in molecular chemistry ) to scientific theories ( the principles of evolution / natural selection are a basis for all ecological sciences ).
18.
As of the 2006 CODATA recommended values, the relative uncertainty in determinations of the Avogadro constant by the X-ray crystal density method is, about two and a half times higher than that of the electron mass method.
19.
If the Avogadro constant was 7.022 ?10 23 instead, that wouldn't make " that " much difference; if it was 6.022 ?10 24 that would make a huge difference.
20.
This number is called Avogadro's number and has the value It is the numerical value of the Avogadro constant which has the unit 1 / mol, and relates the molar mass of an amount of substance to its mass.
