Isotopes. Magnesium Isotope information. Periodic table. Stucture of an Atom. Protons,Electrons and neutrons in an Atom. Ionic and covalant bonding. Relative formals mass. The relative formal of Calcium Carbonate. Cacculating the empirical formula. How to Calculate the Empirical formula of Alumininim ore. Atomic number and atomic mass information. Atomic number and atomic mass of sodium. Atomic number and atomic mass of sodium information.