In order to determine the number of protons in 20.02 mol of Ne, we use Avogadro's number to convert the number of moles to number of atoms, 1 mol = 6.022 x 10^23 atoms. From there, we must know the number of protons in a Neon atom, which is 10. Thus, the formula will be:
(20.02 mol Ne)x(6.022 x 10^23 atoms/mol)x(10 protons/1 atom Ne) =
1.2056 x 10^26 protons
They must obey the Law of Conservation of Mass that states that matter cannot be created or destroyed, it is conserved. Atoms are never lost or gained in chemical reactions, they are rearranged. The mass of the reactants must equal the mass of the products.
