Discusses the use of linear regression methods to extrapolate experimental data. Describes the method of averages and two weighted least squares. Calculates the error range of each method. (YP)

Described are the techniques and results of using this tissue culture activity. Discusses the advantages of using such techniques in teaching alternation of generation life cycles to biology students. (CW)

Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)

Develops a lab experiment for introductory instrumental analysis that requires interference studies and optimizing of conditions. Notes the analysis of the aspirin is by visible spectrophotometric assay. Gives experimental details and discussion. (MVL)

Describes a laboratory experiment designed to encourage laboratory cooperation among individual undergraduate students or groups. Notes each student contributes results individually and the exchange of data is essential to obtain final results. Uses the polarographic method for determining complex metal ions. (MVL)

Describes a laboratory experiment that measures the amount of ascorbic acid destroyed by food preparation methods (boiling and steaming). Points out that aqueous extracts of cooked green pepper samples can be analyzed for ascorbic acid by a relatively simple redox titration. Lists experimental procedure for four methods of preparation. (MVL)

Presents two experiments: the first one measures the heat of an exothermic reaction by the reduction of permanganate by the ferris ion; the second one measures the heat of an endothermic process, the mixing of ethanol and cyclohexane. Lists tables to aid in the use of the solution calorimeter. (MVL)

Describes a demonstration to show the character and behavior of mixing clouds. Discusses laminar and turbulent flow, and the formation of contrails and other cloud phenomena. (CW)

Discusses two strategies that provide concrete-thinking students with opportunities to develop and use formal or critical-thinking skills. Describes using task analysis and long-term investigations in the classroom. (YP)

Discusses the use of direct demonstration of the connections among the science process skills and the content areas of science. (MKR)

Presents activities that enable students to determine the exact time of midday and to use this to plot a north-south line. Uses shadow experiments to teach the concepts of rotation of the earth and calculation of latitude. (JRH)

A major contributor to our understanding of the adaptation of all organisms to the physical environment is physiological ecology. Described here is an inexpensive, reliable and simple experiment to aid in helping students to understand better the acclimation process. (ZWH)

Provides an activity which measures the heat transfer through an insulated cylindrical tank, allowing the student to gain a better knowledge of both the physics involved and the working of spreadsheets. Provides both a spreadsheet solution and a maximum-minimum method of solution for the problem. (MVL)

Describes the Macintosh equipment and software necessary to obtain and use digitized video for motion analysis. Also provides a simple strategy for undertaking such an analysis. (MVL)

Liquid crystal displays are currently utilized to convey information via graphic displays. Presents experiments and explanations that employ the concept of liquid crystals to learn concepts related to the various states of matter, electric and magnetic forces, refraction of light, and optics. Discusses applications of liquid crystal technology.…