Explains that some metal springs have an initial tension that must be overcome before using the F=kx relationship (Hooke's Law) for experimental calculations in the physics laboratory. (WRM)

Explains how to determine the polarity of static electric charges by using an electrician's tool called the test pencil. (WRM)

Suggests specific ways in which laboratory activities might be slightly modified to increase students' understanding in science, based on recommendations from the National Science Education Standards and on constructivist understandings of the learning process. Contains 42 references. (WRM)

Presents a science experiment about oil spills and oil pollution for 7th- and 8th-grade science students. This variation on a method used by pollution control experts to clean up oil spills shows students how oil is collected after an oil spill, explaining that with this method, much of the damage from an oil spill can be averted. (SM)

Introduces a science experiment in which students investigate the wind-leaf relationship by using a leaf blower. Assesses damage differences between leaf species under wind stress. (YDS)

Presents a laboratory experiment on determining the molecular weight of an unknown molecule by using gel filtration chromatography. Describes the procedure and lists required materials. (YDS)

Presents a lab exercise that introduces students to the concepts of community structure, succession, and adaptation by having them make detailed observations from two or more stone walls differing in some historical, environmental, or physical variable. (ASK)

Presents a method to measure the mass of a definite amount of a gas that occupies a known volume at a given pressure in order to determine experimentally the root mean square speed of molecules of a gas. (JRH)

Describes a simple manual apparatus designed to serve as an effective demonstration of the differences between isothermal and adiabatic processes for the general or elementary physics student. Enables students to verify Boyle's law for slow processes and identify the departure from this law for rapid processes and can also be used to give a clear…

Presents activities and investigations that provide a trail of physics-related topics for students to investigate at a bowling alley. (JRH)

Describes an assay to determine the rate of photoreduction of 2,6-dichlorophenolindophenol (DCPIP). Acquaints students with experimental design and teaches them how to evaluate and communicate their results with the goal of enhancing their scientific literacy by integrating basic chemistry and arithmetic into their practical experience. (JRH)

Describes a general chemistry experiment that is carried out in sunlight to illustrate the ability of TiO2 to act as a photocatalyst by mineralizing an organic dye into carbon dioxide. Details about the construction of the reactor system used to perform this experiment are included. (DDR)

Presents suggestions for alternative presentations of some of the material that usually forms part of the introductory chemistry course. Emphasizes development of concepts from experimental results. Discusses electronic configurations and quantum numbers, experimental evidence for electron configurations, deducing the shell model from the periodic…

Presents an alternative approach to teaching reaction thermodynamics in introductory chemistry courses using calculations of enthalpies, entropies, and free energies of atomization. Uses a consistent concept, that of decomposition of a compound to its gaseous atoms, to discuss not only thermodynamic parameters but also equilibrium and…