Science education research has shown that students use causal reasoning, particularly the model "agent--instrument--object," to explain or predict the outcome of many natural situations. Students' reasoning seems to be based on a small set of few intuitive rules. One of these rules quantitatively correlates the outcome of an experiment…

Describes an experiment in which the rate of reaction can be followed using a colorimeter and data can be used to determine order of reaction, rate constant, and energy of activation. (GS)

Suggests several mechanisms for catalysis by metal ion complexes. Discusses the principal factors of importance in these catalysis reactions and suggests reactions suitable for laboratory study. (MLH)

Reports on a technique for illustrating the dependence of the rate of reaction on the concentration of the reactants and for determining the order of reaction with respect to each reactant, the overall order of reaction, the reaction rate constant, and the half-life. (WRM)

Contains articles on digestive enzymes in grasshoppers; bird and badger observation; reactions between hydrochloric acid and sodium carbonate solutions; observing the migration of ions; pupil's heating skills (Bunsen burners); photolysis experimentation; capillary kinetics; experience with trireme; connection circuits; special relativity; a…