Various chromatographic techniques are reviewed, including, among others, elution, liquid-liquid, column-partition, qualitative and quantitative, and plan partition chromatography. (SK)

Described is a conductiometric method for following the course of diffusion of aquated ions through a cellulose membrane. Several experiments using the method are described. (Author/SA)

Discusses forensic science in general and forensic chemistry in particular, including laboratory techniques used by forensic chemists and toxicologists. (SK)

Laboratory procedures, calculations, and sample results are described for a freshman chemistry experiment in which the Clausius-Clapeyron equation is introduced as a means of describing the variation of vapor pressure with temperature and for determining enthalpy of vaporization. (Author/SK)

The status of current techniques and methods of atomic absorption (AA) spectroscopy (flame, hybrid, and furnace AA) is discussed, including limitations. Technological opportunities and how they may be used in AA are also discussed, focusing on automation, microprocessors, continuum AA, hybrid analyses, and others. (Author/JN)

Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…

Describes procedures that students can follow to develop latent prints. An introduction of chemistry of latent prints is also presented. (HM)

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…

Explains an experiment that can be used to help students visualize the phase changes of carbon dioxide. The equipment consists of tweezers and a small plastic syringe. Dry ice is also required. Results are discussed and the phase diagram for carbon dioxide is provided. (DDR)

Given is a rationale for using science demonstrations. The development and characteristics of successful demonstrations are presented. An illustration is given in the area of microbiology. A rating sheet is included. (CW)

An experimental study of 170 undergraduate biology students at a suburban community college revealed that the final evaluation of these students was based more heavily on verbal and written aspects of biology than on practical application of concepts. (IAH)

Describes how paramecium can be identified through the use of DNA-binding fluorescent compounds. The authors used these techniques to test the paramecium stocks from 12 commercial sources. The details of the staining procedures and the results of the commercial tests are presented in this article. (PR)

A low-cost procedure for metallizing a silicon p-n junction diode by electroless nickel plating is reported. The procedure demonstrates that expensive salts can be excluded without affecting the results. The experimental procedure, measurement, results, and discussion are included. (Author/KR)

Describes a research-based activity for high school physics students in which they build an LC circuit and find its resonant frequency of oscillation using an oscilloscope. Includes a diagram of the apparatus and an explanation of the procedures. (DDR)

Investigates procedural understanding of university students at the freshman level, prior to instruction, in the context of experimental work in physics. Proposes two types of reasoning used by students in the laboratory. Indicates a high degree of consistency of these modes of reasoning across experimental phases of data collection and…