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)

Newton's laws can be illustrated by having physics students participate in various activities while on roller skates. Several examples of such activities (including photographs) are provided. (JN)

The camera presents an excellent way to illustrate principles of geometrical optics. Basic camera optics of the single-lens reflex camera are discussed, including interchangeable lenses and accessories available to most owners. Several experiments are described and results compared with theoretical predictions or manufacturer specifications.…

Describes an apparatus used to demonstrate effects observed with polarized light. The apparatus employs two pendulums attached to threads crossing orthogonally over an overhead projector. Several demonstrations using the apparatus are provided. (Author/JN)

Describes advantages of using longer focal-length concave and convex cylindrical mirrors constructed from sheets of flexible, back-surfaced, mirrored acrylic plastic. Suggestions for several student experiments, along with typical experimental results, are also presented. (Author/JN)

Use of spring-wound toy cars in kinematics experiments is described. The cars, used in place of traditional dynamics carts rolling down an inclined plane, are inexpensive, motivational, and give reproducible results. Details of acceleration experiments and suggestions for additional experiments are provided. (JN)

Several good features of a projectile motion experiment (students fire their own rockets) are described, including accuracy achieved, low cost and relative safety. Also described is a simple novelty toy (originally distributed by McDonalds foods) illustrating physics concepts. Blowing on this toy pipe propels a thread around in a loop. (JN)

A significant amount of scientific work is done in laboratories with limited ventilation capabilities. To operate at "acceptable risk", an understanding is needed of what ventilation systems can/cannot do. A simple experiment is described which assesses conditions under which specific experiments should be performed and serves to introduce…

Lists 37 chemicals classified as suspected carcinogens and suspected teratogens (chemicals capable of producing malformations in an embryo). Offers suggestions to high school chemistry teachers for conducting safe laboratory investigations by avoiding use of these potentially toxic materials. (Author/JN)

Describes an 8-week project involving the synthesis of cobalt compounds. Once synthesized, compounds are qualitatively and quantitatively analyzed. Background information, laboratory procedures, and results/discussion are provided for three project experiments. (Author/JN)