Uses a commercially available meat tenderizer for the source of an enzyme that can degrade meat protein and asks students to test the effects of incubating human hair in water with or without this enzyme. Teaches scientific methodology and the importance of experimental controls. (Author/YDS)

Presents a demonstration of sublimation, in which a solid is directly converted into the gaseous state, using an overhead projector. (MKR)

Describes a method to examine preparations of rocks in thin sections between crossed polaroids using a converted biological microscope or a homemade polariscope. (JRH)

Presents experiments for isolating and detecting siderophores produced by bacteria or fungi. (MKR)

This article describes a science learning experience in which intermediate grade students launched balloons with attached postcards to study wind currents. More than 200 (of over 900 balloons) were returned, and their analysis supported the students' hypothesis about the direction of wind currents. (DB)

Presents a simple experiment that enables students to get a quantitative measure of the relationship between the resistance of a wire and the temperature of the wire allowing the calculation of the temperature coefficient of resistance. (JRH)

Laser refractometry is a science-technology-based activity that requires students to manipulate a variety of equipment, tools, materials, and critical-thinking skills. Students use a laser to measure the percent of glucose in a solution by calibrating the system, taking measurements, and computing the concentration. (MKR)

Describes the working of the Adiabatic Gas Law Apparatus, a useful tool for measuring the pressure, temperature, and volume of a variety of gases undergoing compressions and expansions. Describes the adaptation of this apparatus to perform isothermal measurements and discusses the theory behind the adiabatic and isothermal processes. (JRH)

Outlines the use of the toy popularly known as Newton's Cradle or Newton's Balls in illustrating the laws of conservation of momentum and mechanical energy. Discusses in detail the joint effects of elasticity, friction, and ball alignment on the rate of damping of this apparatus. (JRH)

Presents a procedure to demonstrate how the speed of sound in air or within a denser gas can be calculated quickly and accurately in the laboratory. (MKR)

Describes how Newton's Law of Cooling and the Method of Mixtures are used to solve the basic dilemma of whether to add the cool cream to the hot coffee or to let the black coffee cool down first and then add the cream. (ZWH)

Describes how the study of a hurricane can be used to provide integrated basic mechanics in a first-year college course in engineering mechanics. Presents models that predict wind speed given surface eye pressure and several radial dimensions of the storm and calculate total kinetic energy once the wind speed is determined. (ZWH)

Describes simple, inexpensive activities for teaching students about mutants and mutations in bacteria. Explains how to isolate bacteria from soil and leaves and how to grow bacteria on agar or in broth. Describes how to construct a gradient plate for finding the minimum inhibitory concentration of a substance and how to use this set up to find…

Describes the easy collection procedures and classroom uses of live planarians. Suggests that the use of live animals in the classroom will allow students to observe different biological processes exhibited by living organisms. (ZWH)

Uses the Tobacco Hornworm to teach about the competition for limited resources and behavioral changes. Follows three stages during the experiment: (1) brainstorming and hypothesis building; (2) implementation; and (3) data reduction and presentation. (YDS)