Presents an alternative approach to bonding and geometry--the electron domain model--which avoids some of the problems with the conventional approach. Discusses difficulties with the orbital model at the introductory level, electron spin and the Pauli exclusion principle, electron pair domains, nonequivalent domains, multiple bonds, and origins…

Shows how ionization energies provide a convenient method for obtaining electronegativity values that is simpler than the conventional methods. Demonstrates how approximate atomic charges can be calculated for polar molecules and how this method of determining electronegativities may lead to deeper insights than are typically possible for the…

Presents three science activities targeted to help urban students learn about nature: (1) observing coloration patterns of pigeons; (2) measuring local rainfall and comparing it to other areas; and (3) conducting a biodiversity study by observing a patch of lawn. (YDS)

Presents an experiment using plants grown on the classroom window sill that allows students to gain valuable hands-on experience in the collection and analysis of empirical data. (ASK)

Reports on a study to discover physics student teachers' objectives for practical work in teaching physics. Participants took a course based on a unique perceptional approach. Results indicate that after attending the course, student teachers found that the practical work which they had done was very useful. (Author/MM)

Elementary teachers can use weather folklore to help students explore and discover facts about weather. An experiment with woolly bear caterpillars examines whether their stripes can predict what kind of winter weather there will be. A investigation about moon halos and rain gives students experience setting up investigations based on questions…

Presents a physics lab activity in which students determine if an electrode configuration simulates a section of concentric cylinders or concentric spheres. (WRM)

Explains why one orientation of an asymmetric spring-and-mass system leads to a higher frequency of 0000000000 than another orientation. (WRM)

Reports on Westfield State College's Animal Behavior course which requires students to design their own research projects, write a scientific research proposal, conduct experiments, and present results in the form of a scientific paper. (Author/MM)

This study investigates how 25 junior high school students employed their bodies of knowledge and responded to problem cues while individually performing a science experiment and reasoning about a drops phenomenon. Line-by-line content analysis conducted on students' written ad hoc explanations aimed to reveal students' concepts and their…

We report the development of a simplified procedure for restriction fragment length polymorphism (RFLP) analysis of mushrooms. We have adapted standard molecular techniques to be amenable to an undergraduate laboratory setting in order to allow students to explore basic questions about fungal diversity and relatedness among mushroom species. The…

This undergraduate laboratory experiment integrates multiple techniques ("in vitro" synthesis, enzyme assays, Western blotting) to determine the production and detection sensitivity of two common reporter proteins (beta-galactosidase and luciferase) within an "Escherichia coli" S30 transcription/translation extract. Comparison of the data suggests…

An experimental exercise on analytical proficiency studies in collaborative trials is proposed. This practical provides students in advanced undergraduate courses in chemistry, pharmacy, and biochemistry, with the opportunity to improve their quality assurance skills. It involves an environmental analysis, determining the concentration of a…

A laboratory exercise used in the senior biochemistry course at the University of Winnipeg for three years is discussed. It combines liquid chromatography and absorbance spectroscopy and also allows the students to produce a quantitative result within a single three-hour period.

An exciting laboratory environment is activated by the preparation and novel use of magnetic materials to decontaminate water through adsorption and magnetic removal of metals and organics. This uncomplicated technique is also adaptable to the possible application of adsorbents to numerous other environmental substances.