Freshman Organic Chemistry with J. Michael McBride - 4. Coping with Smallness and Scanning Probe Microscopy

Freshman Organic Chemistry (CHEM 125) This lecture asks whether it is possible to confirm the reality of bonds by seeing or feeling them. It first describes the work of "clairvoyant" charlatans from the beginning of the twentieth century, who claimed to "see" details of atomic and molecular structure, in order to discuss proper bases for scientific belief. It then shows that the molecular scale is not inconceivably small, and that Newton and Franklin performed simple experiments that measure such small distances. In the last 25 years various realizations of Scanning Probe Microscopy have enabled chemists to "feel" individual molecules and atoms, but not bonds. 00:00 - Chapter 1. Early Attempts to Visualize Atoms: Clairvoyance 15:39 - Chapter 2. Measuring Small Distances: Newton's Rings and Franklin's Oil-Water Experiment 29:51 - Chapter 3. Scanning Probe Microscopy: Feeling out Electron Pairs 41:23 - Chapter 4. Resonance Structures for H, C, N, O Isomers Complete course materials are available at the Open Yale Courses website: http://open.yale.edu/courses This course was recorded in Fall 2008.