Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)

Presents three models that have been effective for teaching chemical equilibrium and Le Chatelier's principle: (1) the liquid transfer model, (2) the fish model, and (3) the teeter-totter model. Explains each model and its relation to Le Chatelier's principle. (MVL)

Develops a lab experiment for introductory instrumental analysis that requires interference studies and optimizing of conditions. Notes the analysis of the aspirin is by visible spectrophotometric assay. Gives experimental details and discussion. (MVL)

Describes a laboratory experiment designed to encourage laboratory cooperation among individual undergraduate students or groups. Notes each student contributes results individually and the exchange of data is essential to obtain final results. Uses the polarographic method for determining complex metal ions. (MVL)

Describes a laboratory experiment that measures the amount of ascorbic acid destroyed by food preparation methods (boiling and steaming). Points out that aqueous extracts of cooked green pepper samples can be analyzed for ascorbic acid by a relatively simple redox titration. Lists experimental procedure for four methods of preparation. (MVL)

Presents two experiments: the first one measures the heat of an exothermic reaction by the reduction of permanganate by the ferris ion; the second one measures the heat of an endothermic process, the mixing of ethanol and cyclohexane. Lists tables to aid in the use of the solution calorimeter. (MVL)

Describes a demonstration to show the character and behavior of mixing clouds. Discusses laminar and turbulent flow, and the formation of contrails and other cloud phenomena. (CW)

Described are five physics activities including two superconductor projects, synchronizing video camera movements, electrical analysis of a bicycle, and apparatus for the measurement of thermal conductivity. (YP)

Instructional engineering principles were applied to development of instruction in dental mirror skills, and the instruction was validated with 92 students and 25 controls. Measurement of skills over a period of a year and mirror usage during the practical exam indicated instructional effectiveness. Mirror skill instructional tasks are described.…

The first step in engineering the instruction of dental psychomotor skills, task analysis, is explained. A chart details the procedural, cognitive, desired-criteria, and desired-performance analysis of a single task, occlusal preparation for amalgam restoration with carious lesion. (MSE)

Comparison and analysis of the restorative treatment recommendations made by dentists and dental school students for 63 patients found about 85% agreement on treatment plans. It is observed that the results provide some basis on which to assess how well dental school treatments reflect mainstream practice. (MSE)

A survey gathered information on methods of class II amalgam preparation taught in 59 dental schools. Focus was on the teaching and testing of proximal retention groove use, stated rationale for placing retention grooves, and the relationship of the instruction to board criteria for cavity preparation. (MSE)

Contends that, by teaching economics as a laboratory science, using computers, students can be helped to think like economists. Describes computer laboratory exercises and a new economics curriculum being implemented at Denison University (Ohio). (DB)

Classroom demonstrations of selected mechanical properties of polymers are described that can be used to make quantitative measurements. Stiffness, strength, and extensibility are mechanical properties used to distinguish one polymer from another. (KR)

The use of an olfactory acid-base indicator in titrations for visually impaired students is discussed. Potential olfactory indicators include eugenol, thymol, vanillin, and thiophenol. Titrations performed with each indicator with eugenol proved to be successful. (KR)