The exocharmic reactions that can be observed microscopically are discussed. The students can discover the optimal concentration of an acidic lead nitrate solution, so that a crystal of potassium iodide, nudged to the edge of a drop, results in glinting golden hexagons of lead iodide.

Discusses the potential of experiments as a vehicle and to motivate students to use text references to look up further information such as nomenclature, molecular geometry, properties and reactivities for various ions and molecules. Describes the procedures and discussion for three such experiments. (TW)