Recent science reform documents have called for incorporating authentic scientific discourse into science classes as engaging in discourse has shown to result in numerous benefits. Whether these benefits are observed in students depends upon the quality of the discourse in which they engage. However, characterizing the quality of student-student…

Though central to any pedagogical development of physics, the concept of mass is still not well understood. Properly defining mass has proven to be far more daunting than contemporary textbooks would have us believe. And yet today the origin of mass is one of the most aggressively pursued areas of research in all of physics. Much of the excitement…

Problem-based learning, process-oriented guided inquiry learning, and peer-led team learning are student-centered, active-learning pedagogies commonly used in science education. The characteristic features of each are compared and contrasted to enable new practitioners to decide which approach or combination of approaches will suit their…

This paper describes a reproducible process where the irreversibility can be readily evaluated and provides a thermodynamic description of the important phenomenon of hysteresis. A metal hydride is used because hysteresis is observed during the formation and decomposition of the hydride phase. (RH)

Discussed are the discovery of saccharin and dulcin and some examples of what has been learned from the research related to the development of these sweeteners. (RH)

Presented is a method of obtaining accurate rate constants for autocatalytic reactions. The autocatalytic oxidation of dimethylamine by permanganate ion in aqueous solution is used as an example. (RH)

Introduced is a method for estimating carbon-13 nuclear magnetic resonance (NMR) shifts. The method is brief and simple so that students can use it with ease. (RH)

Presented is a general approach and equation for teaching the hydrolysis of salts. This general equation covers many more sets of conditions than those currently in textbooks. The simplifying assumptions leading to the known limiting equations are straightforward. (RH)

Reviews analogies used to try to capture the concept of the magnitude of Avogadro's number, including analogies related to small/tiny objects, counting, people, water, and money. Also presents several new ones which are based on modern computers and printers. (JN)

The cause of the Cretaceous/Tertiary extinction has become a major geologic controversy. Current evidence for the two opposing views is reviewed to provide an introduction to the controversy and to form the basis for a seminar of discussion topic. (Author/JN)

Outlined is a procedure for analyzing the ground electronic state of the iodine molecule by using information provided by "hot" bands, observed in the absorption spectrum of iodine vapor. (RH)

Presented are three methods for dealing with chemical problems involving reaction stoichiometry. (RH)

Discussed are a brief explanation of the function of the vortex tube and some applications for the chemistry laboratory. It is a useful and inexpensive solution to many small-scale laboratory heating and cooling applications. (RH)

Described is a student preparation of YBa2Cu3O8-x, a classroom demonstration of its superconductivity, and an analytical chemistry experiment dealing with the oxidation state of copper in the material. (RH)

Immediately following a lecture discussion on early hominid characteristics and behavior, students participate in a laboratory study of bipedal locomotion based on an analysis of footprints. The development and use of this simulation are described. (JN)