1. Chapters 5/6 Chemical Bonding

2. 2 Types of bonds . .

3. Bonding Types Percent Ionic 100% 50% 5% 0% Difference in Electronegativity 3.3 2.1 0.5 0.0 Ionic Nonpolar Covalent Polar Covalent

4. Types of Bonds Cs - F 4.0 – 0.7 = 3.3 Ionic Bond 3.0 – 2.1 = 0.9 H - Cl Polar Covalent H - H 2.1 – 2.1 = 0.0 Nonpolar Covalent

5. Polar Covalent Shared electron cloud Cl H d+ d- (Slightly positive) (Slightly negative) Polar Covalent – unequal sharing

6. Nonpolar Covalent H H Nonpolar Covalent – equal sharing

7. Properties of ionic compounds Composed of positive and negative ions Ionic compounds form crystals

8. Ionic vs. Covalent compounds Ionic Covalent Lower melting point Lower boiling point Doesn’t form electrolytes Sugar • Harder • Higher melting point • Higher boiling point • Form crystals • Form electrolytes • Salt

9. Metallic bonds Sheet of positive ions surrounded by mobile electrons

10. Metallic bonding • Electrons are randomly spaced • Free to move around • Good conductors of heat and electricity • Called “electron sea” • Properties of metals • Malleable – able to be bent or shaped • Ductile – able to be drawn into a wire

11. VSEPR • Valence shell electron pair repulsion theory • Electrons want to be as far apart as possible • “molecular geometry” • Linear – AB2 • Bent – AB2e2 • Triangular Planar – AB3 • Tetrahedral – AB4