This paper reports on an interview study of 18 Grade 10-12 students' model-based reasoning of a chemical reaction: the reaction of magnesium and oxygen at the submicro level. It has been proposed that chemical reactions can be conceptualised using two models: (i) the "particle model," in which a reaction is regarded as the simple…

School instruction is critical for helping students use energy as a lens for making sense of phenomena, however, students often struggle to see the usefulness of energy analysis for interpreting the world around them. One reason for this may be an over-reliance on the idea of energy forms in introductory energy instruction, which may…

The purpose of this laboratory experiment is to study fundamental concepts of kinetics and equilibria and the isotope effects associated with both of these concepts. The concepts of isotopes in introductory and general chemistry courses are typically used within the contexts of atomic weights and radioactivity. Kinetic and equilibrium isotope…

Elementary, middle-level, and high school science teachers commonly find their students have misconceptions about heat and temperature. Unfortunately, student misconceptions are difficult to modify or change and can prevent students from learning the accurate scientific explanation. In order to improve our students' understanding of heat and…

We observe teachers in professional development courses about energy constructing mechanistic accounts of energy transformations. We analyze a case in which teachers investigating adiabatic compression develop a model of the transformation of kinetic energy to thermal energy. Among their ideas is the idea that thermal energy is generated as a…

In this article, the author reports results in their efforts to model sublimation of carbon dioxide and the associated kinetics order and parameter estimation issues in their model. They have offered the reader two sets of data and several approaches to determine the rate of sublimation of a piece of solid dry ice. They presented several models…

The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

Many high school and introductory college physics courses make use of mousetrap car projects and competitions as a way of providing an engaging hands-on learning experience incorporating Newton's laws, conversion of potential to kinetic energy, dissipative forces, and rotational mechanics. Presented here is a simple analytical and finite element…

This work examines commonly used particulate-level pictures meant to illustrate gases. These pictures are found throughout textbooks in the middle grades through the college level, as well as in questions frequently used to assess conceptual learning in students. This work uses the kinetic-molecular theory of gases to demonstrate the inaccuracies…

We present an analysis of the new French curriculum on chemical changes describing the underlying models and highlighting their relations to the empirical level. The authors of the curriculum introduced a distinction between the chemical change of a chemical system and the chemical reactions that account for it. We specify the different roles of…

Discussed is the idea that models should be taught by emphasizing limitations rather than focusing on their generality. Two examples of gas behavior models are included--the kinetic and static models. (KR)

A model demonstrating the relationship between the structure of blood vessels and the flow of blood is described and illustrated in the biology section of the newsletter. The apparatus also contains a functional (but not structural) model of the heart. Suggestions for the preparation of a relatively permanent dialysis bag from visking tubing are…

Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

Short articles describe a method of introducing the study of simple harmonic motion, and suggest models that are analogues for impedence matching, electrical transformers, and birefringent crystals. (AL)