practice/exercise only. Ionic compound. Electron configuration in neutral atom. Number of electron lost (metal). Number of electron gain (nonmetal). Oxidation number. Electron configuration in ion/s atom. Valence electrons. 1. CaF2 2. K2O 3. MgCl2 4. LiF 5. RbBr. Practice/exercise only. Molecule. Combining atoms and their valence electrons. Electrons needed to become stable. Electron dot structure of molecule. 1. Cl2 Chlorine 2. H2S Hydorgen ulfide 3. Nh3 ammonia 4. CCl4 carbon tetrachloride 5. C02 carbon dioxide