Explains the use of a convex lens as a thick mirror. Shows the expression for the power of this type mirror. (YP)

Describes an instructional experiment that was designed to illustrate the use of periodate oxidation in sugar analysis, and the consequence that the absorbance of mixtures of non-interacting substances is additive. (TW)

Discusses: how thought experiments (TES) are presented and used in physics textbooks; how and why teachers include TES in their explanations; and what understandings students draw from TES. Indicates that TES are only one of a broad class of "acts of imagination" which are essential in physics education. (JN)

Describes three experiments for undergraduates which illustrate associations of parasites with their host. Includes a table of parasite-induced alterations of selected host species. Instructional suggestions are also provided. (ML)

Describes a laboratory experiment which focuses on the importance of water in germination and seedling emergence. Discusses the activity's design, expected results, and possible application. Offers suggestions for extending the experiment. (ML)

Provides guidelines for simple acceleration experiments with string and attached weights as a means to stimulate the reticular activating system (RAS) of the human brain. Several methods (discrepant events, curiosity, choices, and doubt) are suggested for promoting RAS high-level thought. String drop experiments provide concrete experiences with…

Focuses on genetic concepts that form key components of transmission genetics and illustrates how the domestic cat can be used in the teaching of these concepts. Offers examples of how laboratory experiences with the cat can enhance student learning of genetics. (ML)

Methods of investigating plant root growth developed for research purposes can be adopted for student use. Investigations of the effect of water table level and of ethylene concentration are described, and techniques of measuring root growth are explained. (Author/ML)

"Females in Engineering, Methods, Motivation, and Experience" (FEMME) is a precollege program at New Jersey Institute of Technology giving academically talented ninth-grade girls an introduction to engineering. Four experiments (windmill building, burglar alarm construction, electrochemistry, and spatial reasoning activities) helpful in achieving…

Describes the properties of colloids, listing those commonly encountered (such as whipped cream, mayonnaise, and fog). Also presents several experiments using colloids and discusses "Silly Putty," a colloid with viscoelastic properties whose counterintuitive properties result from its mixture of polymers. (DH)

Presents background information and procedures for 12 experiments dealing with such areas as: reactivity of a homologous series of saturated monovalent alcohols; enzymatic degradation of hydrogen peroxide by catalase; effect of an activator and inhibitor on amylase activity; proving the existence of phenol in waste water; detecting common air…

The construction of a diffraction grating spectroscope has been previously reported. A procedure to fit a linear scale to this spectroscope is described (allowing measurement on wavelength of spectral lines without increasing cost of the assembly). Also described are some applications of this modified spectroscope for secondary school laboratory…

Describes a demonstration involving the controlled combustion of a mixture of metals with black and smokeless powder in a small Erlenmeyer flask. Also describes demonstrations using a device that precludes breathing of hazardous vapors during class demonstrations; the device is easy to transport and use in rooms without sinks. (JN)

Describes a simple method for purifying catalase for the study of proteins. Procedures are systematically and diagramatically presented. Also identifies polyacrylamide gel electrophoresis, kinetic studies, and apparent molecular weight determination as possible techniques to be used in studying proteins. (ML)

Presents an experiment which enables weed science students to observe first-hand the process of herbicide leaching in soils. Features of this technique which demonstrate the movement of herbicide within a column of soil are outlined. Diagrams are provided of the apparatus employed in the exercise. (ML)