Total number of fundamental particles in one mole of water is equal to ( N_A = Avogadro's number )

Each oxygen atom, ${\mathrm{O}}_8^{16}$ contains….8 protons, 8 electrons and 8 neutrons ;

Each hydrogen atom, ${\mathrm{H}}_1^1$ contains….1 proton, 1 electron and zero neutrons ;

Thus each molecule of H₂O contains…10 protons, 10 electrons and 8 neutrons ;

Thus each mole (16 g) of H₂O  contains…10 moles (10 N_A) of protons, 10 moles (10 N_A)  of electrons and 8 moles (8 N_A)  of neutrons ;