Chemical Bonding 
      and Molecular Geometry
  • Covalent Bonds 
  • Electronegativity 
  • Polarity of Covalent Bonds
  • Lewis Structures and the Octet Rule
  • Exceptions to the Octet Rule
  • Resonance Lewis Structures 
  • Bond Energies 
  • Calculating Enthalpy using Bond Energy
  • Molecular Shape - The VSEPR Model
              Review of Atomic Properties
    •   Effective nuclear charge & Atomic Size: 
       1. Effective nuclear charge increases left-to-right 
           across periods, and decreases top-to-bottom down 
           a group;
       2. Atomic size decreases left-to-right across periods, 
           and increases top-to-bottom down a group:
       3. Ionization energy incresses left-to-right across a 
           period, and decreases top-to-bottom down a 
           group.
              Review on Atomic Properties
    •   Atomic Size, Ionization Energy, and Electron 
        Affinity: 
       1. L-to-R: atomic size decreases; ionization energy 
           increases; electron affinity increases;
       2. Top-to-bottom: atomic size increases; ionization 
           energy decreases; electron affinity decreases;
                               Ionic Compound
       •  The atoms in sodium chloride (common table salt) are arranged to 
          (a) maximize opposite charges interacting. The smaller spheres 
          represent sodium ions, the larger ones represent chloride ions. In 
          the expanded view (b), the geometry can be seen more clearly. 
          Note that each ion is “bonded” to all of the surrounding ions—six in 
          this case.
         Ionic bonds 
   • Attractions between cations and anions;
   • Bonds formed between metals and 
    nonmetals