All but one of the following statements are true. Which one is not true?

(a) A mass (in grams) equal to the molecular mass (in atomic mass units) of a pure substance contains the same number of molecules, no matter what the substance is.

(b) One mole of any pure substance contains the same number of molecules.

(c) Ten grams of a pure substance contains twice as many molecules as fi ve grams of the substance.

(d) Ten grams of a pure substance contains the same number of molecules, no matter what the substance is. 

(e) Avogadro’s number of molecules of a pure substance and one mole of the substance have the same mass.