Presents an alternative to the use of a radar to determine how fast an individual can serve a tennis ball. Equipped with a tape recorder and a Macintosh computer, students determine the velocity of a tennis ball by analyzing the sounds and echoes heard on the court. (ZWH)

Discusses 5 innovative experiments conducted by Rutherford in early 1900s utilizing the 30 milligrams of radium salt he personally carried from Europe to Canada in 1903. Traces his work with alpha particles from his original results which determined their nature, charge, and mass, to his technique of backscattering which helped to advance…

Presents experiments to measure the velocity of sound through metals and other amorphous materials. Describes the equipment used to make the measurements and the possibility of interfacing with a microcomputer. (MDH)

Presents a cooperative activity between home and school in which parents and students examine the growth of a variety of bulbs. Bulbs are taken home to sprout and returned to school to monitor their growth. Students gather data, hone observation and graphing skills, and communicate with their parents on the project. (MDH)

Presented is an approach to the study of nutrient cycling in the school laboratory. Discussed are obtaining, processing, and incubating samples; extraction of ions from soil; procedures for nitrate and ammonium analysis; data analysis; an example of results; and other aspects of the nitrogen cycle. (CW)

Describes problems in teaching problem solving and summarizes research in this area. Presents Guided Design or Guided Decision Making as a problem-solving approach in which groups of students work their way through a model of the problem-solving process as they wrestle with a discipline-specific situation. (PR)

Provides a student worksheet and set-up instructions for a science experiment to demonstrate the concept of density. Students are asked to explain the phenomenon in which a liquid of lower density placed in the bottom of two vertical flasks flows up to replace the liquid of higher density in the upper flask. (MDH)

Presents an activity to help students understand the precepts of the Hardy-Weinberg principle and simultaneously permit observation of a model of evolution through natural selection in a nonthreatening setting. (PR)

Presents a simple activity designed to allow students to experimentally verify Kepler's second law, sometimes called the law of equal areas. It states that areas swept out by a planet as it orbits the Sun are equal for equal time intervals. (PR)

Describes the federal legislation introduced in 1991 that provides formula grants to states to purchase elementary science equipment. The purchases are to be matched by local education agencies and coordinated with hands-on laboratory activities. (MDH)

If science education is to be related as closely as possible to science, then Thought Experiments (TEs) must play an appropriate part. Presents a typology of TEs with examples drawn from the history of physics and addresses their various uses in bringing about students' conceptual development. Finds appropriate use of TEs is lacking in physics…

Reviews three projects that use a graphing calculator linked to a calculator-based laboratory device as a portable data-collection system for students in chemistry classes. Projects include Isolation, Purification and Quantification of Buckminsterfullerene from Woodstove Ashes; Determination of the Activation Energy Associated with the…

Describes a laboratory exercise that takes advantage of the abundant number of species of goldenrod galls that exist in the environment to explore a question concerning the behavior of the female gall-forming insects as they lay eggs on the goldenrod plant. (ZWH)

Presents information and data on an experiment designed to test whether different atmosphere compositions are affected by light and temperature during both cooling and heating. Although flawed, the experiment should help students appreciate the difficulties that researchers face when trying to find evidence of global warming. (PR)

Describes how to approach block scheduling of science classes. Discusses the planning process, specific activities that work well in longer science classes, and techniques for motivating students. (DDR)