Describes an experiment for undergraduate chemistry laboratories involving a chemical found in plants and some sea animals. Discusses collection and identification of material, a hemolysis test, preparation of blood-coated agar plates, and application of samples. (CW)

The purpose of this study was to determine the concerns of Texas science teachers about the 40 percent laboratory time rule just prior to enforcement and at the end of its first year of implementation. The methodology, results of the first and second years, conclusions, and implications for teaching science are discussed. (KR)

Describes a demonstration procedure using controlled reduction potentials to predict observed color changes which are then experimentally verified. Demonstrates the usefulness of this procedure in helping students understand LeChatelier's principle and the solubilit rule "like dissolves like." (CW)

Discusses the theory and history behind an experiment that will be performed to measure the gravitational forces that effect antimatter. Describes conditions under which the principle of equivalence would be violated or supported. Reviews historical tests of equivalence, current theory and experiments. Presents the design of the new experiment.…

Describes experiments in which students prepare in situ soluble complexes of metal ions with different ligands and observe and estimate the change in formal potential that the ion undergoes upon complexation. Discusses student formation and analysis of soluble complexes of two different metal ions with the same ligand. (CW)

Describes a laboratory exercise in which acid dissociation constants and molecular weights are extracted from sample data and the sample is identified. Emphasizes accurate volumetric work while bringing to practice the concepts of acid-base equilibria, activity coefficients, and thermodynamic constants. (CW)

Describes an application of potentiometry to the determination of acidic and basic compounds in household cleaners in chemistry instruction. Discusses procedures and results of this experiment. (CW)

Investigates the effects of using scientific apparatus versus household objects on the accuracy of primary school children in a simple titration exercise. Indicates no significant difference between the accuracy obtained using the two types of apparatus at the beginning, but improved performance for children using scientific apparatus by the end.…

Described is a study which was developed to find the proportion of cross-dominance in young adults. Procedures and statistical tests are discussed. The tasks used in the assessment of cross-dominance are described. Results indicated that all persons suffered from some cross-dominance. (CW)

Chromium(VI) compounds are classified as oxidizers and must be specially packaged and transported for disposal while Cr(III) compounds are considered nonoxidizers. A process which reduces Cr(VI) to Cr(III) by adding sodium metabisulfite followed by neutralization with magnesium hydroxide is explored. (MVL)

Investigates memory storage and molecular nature of associative-memory formation by analyzing Pavlovian conditioning in marine snails and rabbits. Presented is the design of a computer-based memory system (neural networks) using the rules acquired in the investigation. Reports that the artificial network recognized patterns well. (YP)

In the 20 years since the inauguraion of "Jugend forscht" (Young Researchers) over 26,000 boys and girls have taken part in this annual Olympiad of young innovators. This brochure gives an insight into the diversity of themes dealt with by the "Jufos" (young researchers) and into their ability to achieve astonishing…

Describes an experiment to be performed in an undergraduate biochemistry laboratory that is based on a gradient centrifugation system employing a simple bench top centrifuge, a freezer, and frozen surcose gradient solution to separate macromolecules and subcellular components. (CW)

Describes a kinetic and mechanistic investigation of ascorbic acid by a substitution-inert complex in acidic medium suitable for the undergraduate level. Discusses obtaining the second order rate constant for the rate determining step at a given temperature and comparison with the value predicted on the basis of the Marcus cross-relation. (CW)

Reports on a project in which observations of student and teaching assistant behavior were used to redesign a teaching unit on recrystallization. Comments on the instruction manual, starting points for teaching the unit, and list of objectives with related tasks are included. (JN)