1. Bond Strength
Bond length (the distance between the nuclei of atoms in a covalent bond) decreases with the addition of more shared pairs = stronger bond
Recall: What is “ionization energy”?
Similarly, energy is required to break a bond between atoms in a molecule: bond dissociation energy.

2. Bond Strength (continued)
Which molecule do you think would have the most bond energy: F2, N2, or O2?
Why?
Bond dissociation energies:
F2 = 159 kJ/mol
O2 = 498 kJ/mol
N2 = 945 kJ/mol

3. Assignments  Practice Problems, p.244: 1-5
Study Guide for Content Mastery workbook: p.49 (omit 4 and 5)
Complete worksheets for review of naming compounds and writing formula units.