Describes an activity to study radioactive decay using charged balloons. Reports on readings of radioactivity taken at different locations in Edmonton, Alberta using balloons. (JRH)

Describes factors affecting sand composition and distribution along coastlines. Uses variations in sand types along the Oregon coast to illustrate the influences of sand grain density, wave action, and headlands on sand movements. Describes the seasonal movement of sand across beaches. (DLH)

Presents a set of six activities in population genetics for a college-level biology course that helps students understand the Hardy-Weinberg principle. Activities focus on characterizing a population, Hardy-Weinberg proportions, genetic drift, mutation and selection, population size and divergence, and secondary contact. The only materials…

A hands-on science activity, which calls for students to perform a physical checkup on a local tree, is described. A reproducible worksheet, "A Tree's Annual Checkup," is included. (IAH)

Argues that the concept of optical activity is vague to students because it is difficult for instructors to demonstrate the phenomenon in the classroom. Presents a demonstration that allows students to observe and manipulate the optical path of polarized light through optically inactive and active solutions. (CCM)

Describes a series of activities that help students form accurate conceptions of meiosis and how its process and purpose differ greatly from mitosis. Discusses the concept of crossing over. Uses a small plastic egg to engage students in a fertilization activity. (SAH)

Describes a board game, ImmunoScenarios, which was developed to reinforce the ideas about the immune system discussed in lecture classes. Emphasizes important characteristics of the body's specific defense system including specificity, cooperation among various cells, and memory. Includes directions for playing, student handouts, and scenarios.…

Explains the basics of soil color and the Munsell Soil Color Chart. Presents a chart showing the relationship between minerals and soil color. Introduces a soil color activity. (YDS)

Describes a regional science fair in Indiana. Presents guidelines for organization and registration, rules and regulations, display and presentation, science fair advancement opportunities, and other competitions. (SAH)

Introduces a stoichiometry experiment using Legos or other building-block car kits. Determines the mass relationship between the required components and the final product. Includes both instructor information and a student activity sheet. (YDS)

Introductory students design and carry-out experimental procedures to determine the identity of three unknown gases from a list of eight possibilities: air, nitrogen, oxygen, argon, carbon dioxide, helium, methane, and hydrogen. Students are excited and motivated by the opportunity to come up with their own experimental approach to solving a…

Presents a microscale pH titration technique that utilizes an automatic pipet. A small aliquot (1-5 mL) of the analyte solution is titrated with repeated additions of titrant, and the pH is determined after each delivery. The equivalence point is determined graphically by either the second derivative method or a Gran plot. The pipet can be…

Presents an activity that can be used for acid-base chemistry, everyday chemistry, or food chemistry. Investigates the rising in baked goods. Includes both instructor information and student activity sheets. (YDS)

During a snow bank exploration, students noticed "ice caves," or pockets, in some of the larger snow banks, usually below darker layers. Most of these caves had many icicles hanging inside. Students offered reasonable explanations of ice cave formation--squirrels, kids, snow blowers--and a few students came close to the true ice cave-formation…

The human hand is made up of four fingers and one thumb. This month's "Home Connections" activity will help students understand the importance of the thumb for doing simple, everyday activities. Most primates (humans, apes, and Old World monkeys) and some other animals have opposable thumbs. Humans can move their thumb farther across their hand…