what is the relation between AMU & Mole? also what is the difference between "Molar mass" and "mass" and please, what is mole? I read this on Wikipedia.com: "It is a common misconception that the mole is defined in terms of the Avogadro constant. It is not necessary to know the number of atoms or molecules which are present in order to use the mole as a unit of measurement, and indeed the first measurements of amount of substance predate modern atomic theory and any measurements of atomic weight" and I don`t get it, what is mole after all? and why is it a misconception to define mole in terms of Avogadro constant? and how does mole exactly "work"? I know, lots of questions, I`m just pretty much confused, even my doctor didn't help me... I brought him a paper, and the first thing he wrote was "mole = molar mass", and I was like, Does mole equal molar mass?! is that an equal sign?! and he said "yes"!