Describes a milk bubble machine to be used to demonstrate the acceleration of gravity in the classroom. Instructions are given for the construction of the milk-bubble-acceleration-of-gravity machine. (Author/DS)

Describes a "flat" linear air track, glider and spark timer system for use in the physics laboratory. The results of experimental tests using the system are briefly stated. (SA)

A discussion of the basic design and characteristics of gas chromatography-mass spectrometry systems used in clinical chemistry. A comparison of three specific systems: the Vitek Olfax IIA, Hewlett-Packard HP5992, and Du Pont DP-102 are included. (BB)

Describes and evaluates the Tel-X-Ometer, its performance, and its accessories. The apparatus, with its low intensity x-ray beam, is specifically designed to make x-ray experiments safe, practical, and affordable for the students. (GA)

Describes how to build and calibrate an apparatus utilizing modern circuitry that quickly and accurately measures dipole moments. (MLH)

Describes an experiment in which chemistry students determine the efficiency of a laboratory burner used to heat water. The reaction is assumed to be the complete combustion of methane, CH4. The experiment is appropriate for secondary school chemistry students familiar with heats of reaction and simple calorimetry. Contains pre-laboratory and…

Describes a laboratory exercise containing a practical series of experiments that novice students can perform within two hours. The exercise provides a confirmation of van't Hoff's law while placing more emphasis on osmotic flow than pressure. Students can determine parameters such as the reflection coefficient which stress the interaction of both…

Recommends some measures to take to ensure that demonstrations are carried out safely. Includes a sample checklist to be completed before and after demonstrations. (DDR)

Presents a laboratory procedure that involves students extracting their own DNA from a single hair follicle, using the polymerase chain reaction (PCR) to amplify a polymorphic locus, performing electrophoresis on the PCR products on an agarose gel, and visualizing the alleles to generate a "DNA fingerprint." Discusses theoretical background,…

Describes methods to redevelop lab activities for use in schools with limited resources for proper facilities and equipment. Discusses take-home labs, paper-and-pencil labs, and lab station activities. (JRH)

Reports the use of a heavy duty hacksaw blade and a 1000 turn pick-up coil to form the basis of a mechanical oscillator for a laboratory exercise in mechanical resonance designed for either the elementary undergraduate course or in association with an upper level mechanics course. (LZ)

Describes a sensitive, simple, and inexpensive microrespirator that may be used readily by students. Discusses materials and methods for construction and classroom applications. (LZ)

A method for sample preparation and for the determination of average zinc content in algae using adsorptive stripping voltammetry are described. The students gain important didactic advantages through metal determination in environmental matrices, which include carrying out clean protocols for sampling and handling, and digesting samples using…

An iodometric assay that allows the ground-level ozone concentration to be determined with an inexpensive sampling apparatus and a homemade photometer is described. This laboratory experiment applies a variety of different fundamental concepts including oxidation-reduction chemistry, the ideal gas law, and spectroscopic analysis and also provides…

A novel apparatus that strengthens the connection between research and teaching laboratories and serves multiple purposes is described. A versatile laser apparatus suitable for the undergraduate teaching laboratory that may serve as polarimeter, nephelometer or fluorimeter is designed.