Describes how to determine the mass of a gas in a flexible, lightweight container and argues that the buoyant force of air needs to be taken into account. Recommends the use of mylar and describes equipment preparation. (DDR)

Described is the life cycle of the cellular slime molds Acrasiales. Experiments that can be used to explore the aggregation, migration, and culmination activities of the organism are suggested. Laboratory procedures for culturing these slime molds and listings of biological supply houses and literature references are also given. (MA)

Describes a quick, inexpensive laboratory demonstration of Charles's Law. The opening of a large, round balloon is placed snugly over the mouth of a narrow-mouthed 750-mL Erlenmeyer flask, which is then heated in a strong flame. At end of the full procedure, students easily arrive at the conclusion that the volume of a gas is proportional to…

An exercise that uses a common bacterium, E. coli, in great numbers, to detect a demonstrable change in the ability of some cells to become resistant to the common antibiotic streptomycin is presented. The procedure for preparing and pouring the gradient antibiotic plates is provided. The advantages of using the Basic Fuchsin in the agar are…

Presents a relatively short, simple, safe, and visual method for student preparation of chlorine, bromine, and iodine using reactants and glassware that are easy to obtain and handle. (WRM)

Presents methods that can be used to isolate the enzyme tyrosinase and to assay its activity. Lists instructions for a laboratory activity that has variable but frequently dramatic results. (WRM)

Describes a method for the determination of the velocity of sound using a dual oscilloscope on which is displayed the sinusoidal input into a loudspeaker and the signal picked up by a microphone. (GS)

Suggests that the anatomy of a green pea be studied as the culminating laboratory activity of a botany unit in a biology course. (LS)

Describes features of agglutinin research utilizing the jack bean and suggests similar experiments for biology students that utilize more familiar plants. (LS)

Describes an experiment that generates data for calculating the ratio of molecular separation in a gas to molecular diameter. (GS)

This teaching module was developed by the project "Recent Developments in Science and Technology with Applications for Secondary Science Teaching." Premises about students and their learning and generalizations about content are described. Chapters included are: (1) "Introduction"; (2) "Monomers into Polymers"; (3) "Natural Polymers"; (4)…

Demonstrations of Boyle's Law and of the relationship of gauge pressure and atmospheric pressure are presented. (BB)

A demonstration related to current transport through a superconductor is presented. The principle of the experiment, procedures for the demonstration, and technical data are provided. (CW)

A room-temperature demonstration of a floating magnet using a high-temperature superconductor is described. The setup and operation of the apparatus are described. The technical details of the effect are discussed. (CW)