Suggests a threefold rationale for practical work in science: in developing laboratory skills, in learning to work as a scientist, and in acquiring a feel for phenomena. Three types of pupil practical work (exercises, investigations, and experiences) are then discussed. (Author/JN)

Cyclic voltammetry is a simple experiment that has become popular in chemical research because it can provide useful information about redox reactions in a form which is easily obtained and interpreted. Discusses principles of the method and illustrates its use in the study of four electrode reactions. (Author/JN)

Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)

Examines the basking postures of captive eastern painted turtles exposed to two different sources of illumination (white floor lamps and infrared heat lamps) and three types of substrates (sphagnum, rock, wood) and discusses possible ecological and evolutionary significance of these behaviors. (Author/JN)

Spatial filtering, based on diffraction/interference of light waves, is a technique by which unwanted information in a picture ("noise") can be separated from wanted information. A series of experiments is described in which students can create a system that functions as an optical computer to create clearer pictures. (Author/JN)

Five papers presented at the Seventh Biennial Conference on Chemical Education (Stillwater, Oklahoma 1982) focused on qualitative analysis curricula and instruction. Topics included benefits of qualitative analysis, use of iodo/bromo-complexes in qualitative analysis schemes, lecture demonstrations, and brief descriptions of three courses. (JN)

An apparatus is described in which effects of pressure, volume, and temperature changes on a gas can be observed simultaneously. Includes use of the apparatus in demonstrating Boyle's, Gay-Lussac's, and Charles' Laws, attractive forces, Dalton's Law of Partial pressures, and in illustrating measurable vapor pressures of liquids and some solids.…

Citing several disadvantages in using traditional gold-leaf electroscopes in schools, a simple and easily constructed electroscope, suitable for both O- and A-level physics, is described. Information on adapting the electroscope to become a pulse electrometer is provided. Electroscope activities/demonstrations are also provided. (Author/JN)

Describes modification of a chemical reaction to a single 4 1/2-hour laboratory period. Reaction kinetics between 2, 4-initrochlorobenzene and piperidine to form 2, 4-dinitrophenyl-piperidine and piperidinium hydrochloride are followed conductometrically at three temperatures to obtain data to calculate activation parameters. (Author/JN)

Three experiments using merocyanine M suitable as an integrated laboratory experience for undergraduates are described. Experiments demonstrate: complete molecular cycle composed of photochemical, thermal, and protolytic reaction steps; kinetics of cis-trans isomerization of the dye; and mechanism of base catalysis for thermal isomerization of the…

Effect of the "polarity" of low-polarity solvents on the amount of swelling produced in a solid polymer (demonstrated in an organic chemistry lecture) is also suitable as a laboratory experiment. Students can be assigned to a small group of solvents from the list provided. Procedures and materials needed are included. (Author/JN)

Some inherent instrument capabilities/limitations can be described in terms of signal to noise ratio (S/N). Two three-hour experiments are described to give students appreciation of the importance of signal strength and noise level in instrument performance and how S/N can be increased by choice of conditions and data manipulation. (Author/JN)

Three experiments demonstrating basic properties of the active transport system in the Malpighian tubule are described. These include a demonstration of dye uptake by the tubule, effect of metabolic inhibitors on dye uptake, and temperature effects on active transport. (JN)

A college level plasmolysis experiment, demonstrating principles of cell/water relations, has been modified to demonstrate the objective collection of data. Background information, laboratory procedures, results, and instructional strategies are provided. (Author/JN)

Discusses calculations used in chemistry which depend on: (1) linear relationships, (2) quadratic equations, and (3) the exponential function. Also discusses working with inequalities. (JN)