Arrangement of electrons and how atoms combine: Dalton, Thomson, Rutherford, Bohr, etc. History of the picture of the atom. We build up the first 18 atoms by adding protons, neutrons, and electrons. How Atoms Combine: An animated love story of chlorine and sodium. At the disco, atoms combine in various ways. Carbon forms bucky tubes and balls, we see evolving molecular shapes CO2, H2O, NH 3, CH4. Some atoms dance in pairs, e.g. N2. Chlorine is asked to dance with Ca, Al and O but waits for Na. They dance and transfer an electron. Love at last. .