Avogadro's number vs. the Kofh Number

Surely you mean Carbon-12 as the standard atom to base atomic weight units on?

Well, how convinient of a number you wish to use is of course based on what kind of accuracy you want. The text book I used more or less just settled for saying "It's experimental" and put a nice 4 decimal digits on it. Easy enough for students to use.I don't really see what the deal is, though. It's a number experimentally derived in relation to other defined units... Obviously, the more accurate the experiments and calculations, the better.I do hope that the common text-books at least mention the sort of experiments required and just don't show convertion rate formulas, which, as you say, has no actual use in determining the number.[This message has been edited by Melchior, 04-29-2004]

No, we can not agree on that. It's incorrect. You can't just add all the weights of the particles to get the weight of an atom composed of them.Bonding energy does wonder for messing up weight. Atomic bombs takes advantage of this. And they work, as we've seen before.Check any periodic table, and you'll see that the simple 'add everything together' rule don't work out with the numbers listed.ADD: The phenomena that you might wish to check up is usually called 'mass defect' or 'mass deficiency' and would probably be best explained by a low-mid level physics course/textbook or a direct web-search (plenty of .edu sites out there).[This message has been edited by Melchior, 04-30-2004]

Well, by definition, all elements contains the exact same number per mole.What it is exactly that the mole counts differs, yes. For example, a mole of water is based only upon the number of molecules. A mole of hydrogen atoms is based only upon the number of atoms. But the number Na is not dependant on what element you count in any way.The number of gluons is completely irrelevant if you are counting atoms.