Describes an experiment where the gram-equivalent mass of an unknown metal is determined by reacting the metal with dilute hydrochloric acid and collecting the evolved gas over water. This simple, reliable experiment routinely gives results within 1% of the accepted value. (PR)

Describes four activities to analyze drinking water for its pH, hardness, turbidity, and conductivity. (MDH)

Describes four experiments that enable students to explore the phenomena of evaporation and condensation and determine the relative humidity by measuring air temperature and dew point on warm September days. Provides tables to calculate saturation points and relative humidity. (MDH)

Nitrate assimilation by plants provides an excellent system for demonstrating control of gene expression in a eukaryotic organism. Describes an assay method that allows students to complete experiments designed around the measurement of nitrate reductase within a three-hour laboratory experiment. (PR)

Explains how sweet potato roots can be used for plant tissue culture for biology laboratory instruction. (PR)

The Hands-On and Far-Out Physics project is part of the Center for Technology, Environment, and Communication (C-TEC), a project-based learning community at Piner High School in Santa Rosa (California). This article introduces the project team, discusses member activities, presents a walking-speed experiment, and describes a Mars Colony course…

Presents three experiments to introduce students to different kinds of chromatography: (1) paper chromatography; (2) gel filtration chromatography; and (3) reverse-phase liquid chromatography. Written in the form of a laboratory manual, explanations of each of the techniques, materials needed, procedures, and a glossary are included. (PVD)

Presents an approach that can help students to understand what happens in an experiment. Uses overlapping transparencies of both the experiment and the analysis. Includes details of the experiment and transparency preparation. (DDR)

Finds that interpretation of Galileo's only known experimental manuscript produces some interesting questions that offer pedagogical applications. Promotes classroom "research games" consisting of reconstructed experiments with Galileo's inclined plane and with other instruments to allow further speculation. (Author/WRM)

Describes a safe but qualitative alternative to an experiment in which bullets are shot into wooden blocks from below, with some bullets hitting the blocks in the center and others off-center. Explains why the off-center blocks reach greater heights in spite of the fact that the bullet's energy is divided between translational and rotational…

Describes a "dry laboratory" using data from virtual rats to help students understand the hormonal regulation of gastrointestinal function. (Author/WRM)

Presents the rigor mortis process in brook charr (Salvelinus fontinalis) as a tool for better understanding skeletal muscle metabolism. Describes an activity that demonstrates how rigor mortis is related to the post-mortem decrease of muscular glycogen and ATP, how glycogen degradation produces lactic acid that lowers muscle pH, and how…

Discusses the Occupational Safety and Health Administration's (OSHA's) Laboratory Safety Standards as the major driving force in establishing and maintaining a safe working environment for teachers and students. (Author)

Discusses the merits of the Spectrum Techniques gamma spectroscopy system as used by university students to determine the mass-energy of an electron from measurements of the energies of Compton-scattered gammas. (WRM)

Contends that mud dauber nests--which are widely available, safe, inexpensive, and easy to use--offer a novel and highly motivating way to teach ecological concepts to life science students at many grade levels. Presents background information for teachers, details classroom-tested methods for nest dissection, provides keys to nest contents, and…