Discusses the model for all atoms which was developed on the same basis as Bohr's model for the hydrogen atom. Calculates the radii and the energies of the orbits. Demonstrates how the model obeys the de Broglie's hypothesis that the moving electron exhibits both wave and particle properties. (Author/ASK)

Describes an alternative to teaching ecology by using bacteria to test competitor survival. Students observe a time-dependent selective killing of other unrelated bacteria by Pseudomonas aeruginosa. (SAH)

Presents an activity that is foolproof for children to collect and observe soil animals, alive and in the animals' own environment. (ASK)

This activity explores two types of plastic molding and allows students to make their own plastic bottles. (MKR)

Provides descriptions of Physics Olympics events in which physics students collect acceleration data while riding on amusement park rides. (MKR)

Details a laboratory experiment focusing on the relationship between the structure and function of the tracheary elements of the xylem. (MKR)

Presents activities designed to introduce the concept of fossils to middle school students and to clarify students' misconceptions about what is, and is not, a fossil. (JRH)

Describes the use of carbide lights as an excellent mechanism for introducing or reviewing many basic chemistry concepts including elements and compounds, endothermic and exothermic reactions, physical and chemical changes, and balancing chemical equations. (JRH)

Discusses enzymes, catalysts, and factors that affect the rate of a chemical reaction. Presents activities based on enzyme action on hydrogen peroxide and lactose intolerance. (Author/JRH)

Presents an illusional arena by offering experience in optical illusions in which students must apply critical analysis to their innate information gathering systems. Introduces different types of depth illusions for students to experience. (ASK)

Presents a microbiology experiment on how to make soft pretzels with different flours and analyze the results using regression models. (Contains 12 references.) (ASK)

Indicates the difficulties of teaching concepts beyond light and color and creating memorable learning experiences. Recommends sequential activities using the mystery box approach to explain how scientists and doctors use photon applications. (YDS)

Describes an activity for observing the pressure differences between mountain air and sea level air by bottling air. (YDS)

Introduces an activity concerning air pressure. Using an egg and a heated bottle, the air inside the bottle draws the egg into the bottle. (YDS)