CHEM 125A - Freshman Organic Chemistry I
Lecture 02 - Force Laws, Lewis Structures and Resonance. Professor McBride begins by following Newton's admonition to search for the force law that describes chemical bonding. Neither direct (Hooke's Law) nor inverse (Coulomb, Gravity) dependence on distance will do - a composite like the Morse potential is needed. G. N. Lewis devised a "cubic-octet" theory based on the newly discovered electron, and developed it into a shared pair model to explain bonding. After discussing Lewis-dot notation and formal charge, Professor McBride shows that in some "single-minimum" cases the Lewis formalism is inadequate and salvaging it required introducing the confusing concept of "resonance." (from oyc.yale.edu)
| Lecture 02 - Force Laws, Lewis Structures and Resonance |
| Time | Lecture Chapters |
| [00:00:00] | 1. Newton's "Additions": An Inquiry into Small Forces |
| [00:09:16] | 2. Is There a Chemical Force Law? |
| [00:18:27] | 3. The Morse Potential |
| [00:21:42] | 4. What Are Bonds? Early Understandings of Valence |
| [00:32:52] | 5. Deriving Structure and Reactivity from Valence Electrons |
| References |
| Lecture 2 - Force Laws, Lewis Structures and Resonance Instructor: Professor J. Michael McBride. Resources: Professor McBride's website resource for CHEM 125 (Fall 2008). Transcript [html]. Audio [mp3]. Download Video [mov]. |
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