Sodium loses an electron to from sodium ion.
Na -->Na+ + e-
for 100 moles of each sodium atom and sodium ion there would be difference of 100 moles of electrons.
mass of 100 moles of electron = 5.48002g
mass of 1mole of electron = (5.48002/100)g
mass of 1electron = 5.48002/100*6.022*10 (power )23