What does 1 mole in chemistry mean?

Because the atomic weight scale is numerically preserved in the definition of gram atomic weights, the mass of 1 gram-atomic weight of any element could be ... What is invariably used (except for sample calculations in chemistry textbooks; see below!) is the fact that 1 mole of substance is its formula weight in grams. read more

In chemistry, one mole of an element or substance is equal to: (a). its molecular weight in gram e.g. 18 gram water = 1 mole water. (b). its 6.022 x 10^23 molecules (or atoms or ions, whatever we are talking about). read more

Since the unified atomic mass unit (symbol: u, or Da) is defined as 1/12 of the mass of the 12 C atom, it follows that the molar mass of a substance, measured in grams per mole, is numerically equal to its mean atomic or molecular mass measured in Da. read more