Presented is a comprehensible structural representation of humic substances. A number of important roles of soil organic matter, including contribution to the cation-exchange capacity, binding of pesticides, and formation of complexes with micronutrient cations, are illustrated. (Author/CW)

Introduces different methodological strategies in analyzing potential energy surfaces (PES) used in chemical reactivity studies. Discusses the theory of PES and gives examples to be used for student work. Provides procedures for calculating normal coordinates and vibrational properties of an activated complex. (ML)

Calculates an approximation to Avagadro's number for one mole of water by assuming the mole to be in cubical form and then halving the cube three times, thereby doubling the surface area of the original cube. The calculations are derived from the work necessary to perform these divisions. Presents calculated values for several liquids. (MDH)

Outlines the development of a curriculum in molecular science that prepares those students who have a deep understanding of chemistry concepts and principles, have collaboration skills, are able to use modern technology, and can write about chemistry. (DDR)

This study explored preservice teachers' (n = 25) knowledge structures and their mastery of content knowledge in relation to their ability to diagnose the strengths and weaknesses of a fourth grader's videotaped explanations of a scientific phenomenon, i.e., molecular kinetic properties of air. Participants' knowledge structures were analyzed…

Questions the use of the Reactivity Selectivity Principle (RSP) by teachers and authors of texts in discussing organic reaction mechanisms. Provides some applications and failures of the use of the RSP, reviews some quantitative aspects of the RSP, and discusses some of the rationalization of the RSP failures. (TW)

Explores graph theory and use of topological indices to predict boiling points. Lists three indices: Wiener Number, Randic Branching Index and Molecular Connectivity, and Molecular Identification numbers. Warns of inadequacies with stereochemistry. (ML)

Describes a graduate course designed to teach the noncrystallographer how to read a structure paper critically. The course combines formal didactic instruction with student seminar presentations of specific papers from the crystallographic literature. Includes a course outline. (CW)

Reviews three softwre packages: "Molecular Graphics on the Apple Microcomputer, Enhanced Version 2.0"; "Molecular Graphics on the IBM PC Microcomputer"; and "Molecular Animator, IBM PC Version." Packages are rated based on ease of use, subject matter content, pedagogic value, and student reaction. (CW)

Reviews a method for determining oxidation numbers in covalent compounds and balancing mixed organic-inorganic or purely organic systems. Points out ambiguities presented when adjacent atoms have small or zero electronegativity differences. Presents other limitations that arise when using electronegativity values. (CW)

Reviews interesting and useful electrical, magnetic, and optical properties of the organic solid state. Offers speculation as to areas of fruitful research. Discusses organic superconductors, conducting organic polymers, organic metals, and traces recent history of creation of organic metals. (JM)

Describes the design, construction, and use of oversize lecture-demonstration atomic/molecular models. These models appeal to both concrete and formal operational students. Also describes construction and use of an "spdf" sandwich board and an experiment using attribute blocks. (JN)

This article focuses on the nature of acidity in pulp paper as found in comic books and library collections. Some of the various factors that contribute to the deterioration of paper are considered from a chemical perspective. (CW)

The construction of a model that is useful for teaching stereochemistry from a sealed empty envelope is described. Detailed steps with accompanying diagrams are given. (CW)

The construction of a model that is useful for teaching stereochemistry from two sealed empty envelopes is described. Detailed steps with accompanying diagrams are given. (CW)