1. Chemical Bonding
Sections 1-3

2. Objectives Identify types of chemical bonds Analyze ionic bonding
Compare and contrast ionic and covalent bonding
Identify single, double, and triple bonds

3. Key Terms Chemical bond Ionic bond Covalent bond Metallic bond
Lewis symbol
Octet rule
Lattice energy
Lewis structure
Single bond
Double bond
Triple bond
Bond length

4. Chemical Bonds Strong attachment between two atoms/ions 3 Types Ionic
Covalent
Metallic

5. Lewis Symbols Also known as electron-dot symbols
Named for American chemist
Shows only valence electrons
PRACTICE: Nitrogen, Oxygen, Bromine

6. Octet Rule
Atoms tend to gain, lose, or share electrons to get 8 valence electrons
Full s and p
Many exceptions BUT good framework

7. Ionic Bonding Electrons transferred from atom to atom
Cation and anion formed
Electrostatic forces exist between ions of opposite charge

8. Ex: NaCl
Na Cl  Na+ + [ Cl ]-

9. Energetics of Ionic Bond Formation
Formation is exothermic (spontaneous)
Attraction of opposite charges releases energy when stabilized

10. Lattice Energy
Energy required to completely separate a mole of a ionic compound into its ions
+ if separating
- if forming

11. Magnitude of Lattice Energy
Charge of ions
Ionic size
Arrangement of solids

12. Trends
Lattice Energy as charge of ions
and radii

13. Polyatomic Ions Do not forget about them!
They are often anions (or cation for NH4+) of ionic compounds

14. Covalent Bonding
Majority of substances
Sharing of pairs of electrons

15. Lewis Structure Electron-dot diagrams for molecules
Dots represent lone pairs of electrons
A line represents shared electrons

16. Lewis Structures
H-H
H ö: H

17. Multiple Bonds Single bond- 1 pair of electrons are shared
Double bond- 2 pairs are shared
Triple bond- 3 pairs are shared

18. Single Bond

19. Double Bond

20. Triple Bond

21. Bond Length Distance between nuclei of atoms in a bond
Decreases as number of shared pairs increases

22. Homework
even (not 10 or 18) on page 336