1 mol is the amount of substance that contains the same number of particles as there are atoms in 12.0 g of carbon-12.

1 mol is the amount of substance that contains the same number of particles as there are atoms in 12.0 g of carbon-12.

while a mole of water contains the same number of water molecules. (That's about 18 grams, or 0.6 fluid ounces.) The bottom line: A lot of folks leaned about Avogadro's constant this week.