Presents results of a two-year study regarding factors causing student difficulties in performing investigative activities in a beginning biology course. Also investigates the usefulness of written guidelines in alleviating these difficulties. A model for student investigations is proposed. (CS)

Described are experiments to give students experience in the synthesis of peptides from amino acids and to use visible spectroscopy to measure a rate of reaction. The activities were designed for undergraduate courses. (RH)

Described is a laboratory activity to determine five unknown organic compounds. The procedures are designed to help students determine unknowns from a series of tests. (RH)

Described is an experiment that uses nuclear magnetic resonance to study the anomalous paramagnetism of iron(III) chelates. (RH)

Presents demonstrations, using microprocessors, to show the slow change in relative phase of two sine waves feeding the inputs of an oscilloscope and Fourier synthesis. (SK)

Describes the theory and application of an atomic fountain which pushes the atoms by laser pulses. Discusses the applications in measuring atomic properties and in building an atomic clock. (YP)

Proposes a simple procedure based on an expansion of the exponential terms of Raoult's law by applying it to the case of the benzene-toluene mixture. The results with experimental values are presented as a table. (YP)

A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)

Describes procedures and semi-micro reaction apparatus (carbon dioxide trap) to demonstrate how a particular enzyme (L-Glutamic acid decarboxylase) may be used to determine the site or sites of labeling in its substrate (carbon-14 labeled glutamic acid). Includes calculations, solutions, and reagents used. (Author/SK)

Investigates the nature of catastrophic volcanism and the rifting process. Describes two kinds of evidence: quantitative descriptions of rock melting and a wide range of observations. Discusses examples of continent growth in the North Atlantic, India and the Seychelles islands, and the South Atlantic. (YP)

Describes a comparison of scale of laboratory with respect to time efficiency. Compared full scale and one-tenth scale Grignard reactions with full scale averaging 330 minutes to completion and scaled-down averaging 204. Savings are seen in air pollution, toxicity, solvent cost, and time. (JM)

Determined student opinion of the investigative laboratory by surveying both students who had completed an introductory biology course using this format and another group of more advanced students who had taken other courses since this one. Results show that a majority of students feel the format improved their problem-solving skills. (JN)

Described is a gel diffusion experiment that permits the completion of duplicate diffusion runs within a three-hour laboratory session. Information included for the short-duration gel diffusion experiment is the diffusion cell, the experiment, data treatment, and the expected results of the experiment. (Author/DS)

Examines the psychology of learning and its application to work in the laboratory. States that the working memory capacity of students is limited; therefore the amount of information they can process needs to be controlled and "recipe following" in the laboratory is perfectly reasonable. (RT)

Examines the usefulness of cyclic voltammetry to the determination of a complex compound's stoichiometry. Discusses the experimental design, laboratory equipment, and results. (CW)