Describes efforts in devising a method for determining sulfate quickly and accurately from rainwater samples. Explains the design and operation of the apparatus and identifies the solutions for the testing. (ML)

Presents as part I of a two-part series a study involving the intercellular transfer of bacterial DNA that codes for the resistance to antibiotics. Demonstrates to students that such transfers occur. Discusses laboratory procedures, materials and results. (CW)

Describes two experiments for demonstrating the properties of osmosis and semipermeable membranes. Gaseous and liquid osmosis are studied through the use of common laboratory chemicals and equipment. Offers explanations for the phenomena with diagrams. (ML)

Explains that triglycerides consist of a mixture of different compounds, depending on the total number of fatty acid constituents. Details the method and instrumentation necessary for students to analyze a vegetable oil for its triglyceride content. Describes sample results. (CW)

Presents the organization of a one-semester graduate course in structural chemistry including lectures and problems. Discusses the coverage of diffraction from real crystals and structure determination. Summarizes experiments on real crystals conducted by students in the X-ray laboratory. (CW)

Demonstrates a method of measuring the acceleration due to gravity. Provides an illustration of the apparatus and the data analysis. Suggests four different variations of this experiment. (YP)

Describes a simple high-performance liquid chromatography experiment for undergraduate biochemistry laboratories. The experiment illustrates the separation of polypeptides by a step gradient elution using a single pump instrument with no gradient attachments. Discusses instrumentation, analysis, a sample preparation, and results. (CW)

Describes an experiment in which students are given a naturally occurring oligosaccharide as an unknown and are asked to determine both its monosaccharide composition and its structure. Discusses methods and experimental techniques including thin layer chromatography and the use of enzymes. (CW)

Discusses the need for student research-type chemistry projects based upon "unknown" metal complexes. Describes an experiment involving the product from the reaction between cobalt(II) chloride, ethane-1,2-diamine (en) and concentrated hydrochloric acid. Outlines the preparation of the cobalt complex, along with procedure, results and…

Describes nine chemistry demonstrations that can be done using an overhead projector. Includes demonstrations on common ion effect, crystal formation from supersaturated solutions, making iron positive with nitric acid, optical activity, carbon dioxide in human breath, amphoteric hydroxides, the surface tension of mercury, and natural acid-base…

Examines the definitions of scientific observation used in assessing students in Great Britain for the General Certificate in Secondary Education (GCSE). Proposes an instruction framework that supports such definitions. Provides examples of observational tasks and some methods of evaluating them. (TW)

Describes 20 teaching activities and experiments appropriate for use with various secondary school science classes. Instructional activities include the study of catalase, raising bees, a game about equilibrium, spectrometers, lead iodide, resonance, graphing, and electromagnetic waves. (TW)

Describes two demonstration experiments. Outlines a demonstration of the general principle of positive and negative feedback and the influence of time delays in feedback circuits. Elucidates the principle of negative feedback with a model of the iris of the eye. Emphasizes the importance of feedback in biological systems. (CW)

Describes an experiment that provides a study of the different colors and shapes of crystals of transition metal dimethylglyoxime complexes with the use of a low power microscope. Discusses the preparation and examination of the crystals. (CW)

Presents an experimental example illustrating the most common methods for the determination of kinetic parameters. Discusses the different theories and equations to be applied and the mechanism derived from the kinetic results. (CW)