Considered are the underlying ideas of nucleophilic substitution and some of the misconceptions regarding this topic. Discusses methods for teaching this topic and includes definitions for key ideas and terms. (Author/CW)

To integrate a research/discovery component into one course, an experiment using the sea urchin embryo system is introduced because the teacher manages only one organism and students provide the variables. The materials, handling methods, and experimental methods of the experiment are described. (YP)

Described is a laboratory exercise designed to introduce students to the theory and practice of gene mapping including RNA extraction, sucrose density gradient centrifugation, labelling of nucleic acids in vitro, DNA extraction, digestion of DNA with restriction enzymes, and the southern hybridization analysis. Procedures and sample results are…

Described is the use of ordinary ceramic magnets to replace the more expensive bar magnets commonly used. Suggestions for 11 task cards to help introduce children to the uses and principles of magnetism are provided. (CW)

Describes some experiments showing both qualitatively and quantitatively that aerodynamic lift is a reaction force. Demonstrates reaction forces caused by the acceleration of an airstream and the deflection of an airstream. Provides pictures of demonstration apparatus and mathematical expressions. (YP)

Explains the lifting force based on Bernoulli's law and as a reaction force. Discusses the interrelation of both explanations. Considers accelerations in line with stream lines and perpendicular to stream lines. (YP)

Provides the apparatus setup, experimental method, necessary formulas, and references for three measurement experiments: (1) "Determine the Magnetic Induction of a Coil with a Hall Element"; (2) "Measuring Magnetic Force and Magnetic Field of Small Permanent Magnets"; and (3) "Measurements of Sound Velocity by Means of PZT" (piezoelectric…

Presented is a laboratory exercise designed to demonstrate the effects of moisture on hay preservation products in a manner that does not require large amounts of equipment or instructor time. Materials, procedures, and probable results are discussed. (CW)

The Moire pattern is the shimmering pattern which looks like an odd interference pattern in window screens or folds of nylon shower curtain. Illustrates some of the ways the effect may be used, including demonstration of wave interference, detection of small displacement, persistence of vision, contour measurement, beats, and optical clearness.…

Discussed are accidents that occur in the laboratories of highly trained chemists. Four examples are provided to illustrate potential hazards that are often overlooked in chemistry laboratories, molten inorganic salt baths, the reaction of acetone and hydrogen peroxide, halogenated acetylene compounds, and the reaction of hydrogen peroxide and…

Discussed are applications of robotics in the chemistry laboratory. Highlighted are issues of precision, accuracy, and system integration. Emphasized are the potential benefits of the use of robots to automate laboratory procedures. (CW)

Presented is an activity that uses ground ivy to display different growth forms under different light intensities. Specimen preparation, materials, procedures, and probable results are discussed. Examples of graphs of the data are provided. (CW)

Described is a mechanically driven device for generating three-dimensional harmonic space figures with different frequencies and phase angles on the X, Y, and Z axes. Discussed are apparatus, viewing stereo pairs, equations of motion, and using space figures in classroom. (YP)

Describes a demonstration that shows the absorption spectrum of chlorophyll. Uses an overhead projector, a solution of chlorophyll, and a diffraction grating. (RT)

Outlined is a procedure for the assessment of fungal growth under different cultural conditions, together with a demonstration of the toxic nature of exudates released from a fungal pathogen during growth in culture, using a simple bioassay. (Author/CW)