Answer: is the same for all substances.
Step-by-step explanation:
The number of molecules in one mole of a substance is the same for all substances because
A mole (which is the quantity of a substance that has the same number (Avogadro's number, is 6.022 * 10^23) of particles as are found in 12.000 grams of carbon-12 of the substance) for any substance has the same number of atoms, molecules, or ions contained in any other substance.
1 mole = 6.022 x 10^23 atoms, molecules, or ions