Lewis structures (also known as Lewis dot diagrams, electron dot diagrams,and electron dot structures) are diagrams that show the bonding between atomsof a molecule and the lone pairs of electrons that may exist in the molecule. PbO is ionic compound.In an ionic bond, one atom looses all its outer electrons (leaving behind a filled inner shell) while another atom gains electron(s) to fill its valence shell. The two ions attract each other according to Coulombic interactions. . . (Pb2+) (: O : 2-) ' '