Mole Concept

One mole of any substance contains a fixed number (6.022×10²³) of any type of particles (atoms or molecules or ions) and has a mass equal to the atomic or molecular weight, in grams. Thus it is correct to refer to a mole of helium, a mole of electrons, or a mole of Na⁺ , meaning respectively Avogadro’s number of atoms, electrons or ions.