On Sun, May 08 2011, Alan McKinnon wrote: > Apparently, though unproven, at 00:14 on Monday 09 May 2011, john did opine > thusly: > >> Great widgets. Not sure what a Molar Mass Calculator does? Perhaps >> weighs your teeth?? > > :-) > > "Molar" as in the adjective describing "mole" as in "quantity of matter" as > in > "some gigantic number of identical atoms (or maybe it's molecules)". It's a > very useful measure of "some quantity of stuff". > > IIRC the gigantic number is Avogadro's number, on the order of 10^124. So one > mole of hydrogen would be the amount of hydrogen containing that number of > hydrogen atoms (or maybe it's molecules. Whatever.)
6.022 x 10^23 The number of atoms (or molecules) needed so that the weight in grams is the atomic (or molecular) weight. Helium has atomic weight of ~4, so 6.022*10^23 atoms of helium weight about 4 grams. allan
