Describes an experiment on light trapping in thin liquid films. Injection of a thin layer of solution at the boundary of a moving solvent is utilized to create a thin fluid sheet having an index of refraction greater than that of the surrounding medium. (Author/SA)

Describes a short undergraduate experiment which helps in explaining the concept of entropy and in illustrating the second law of thermodynamics. (GA)

Describes potentially dangerous classroom situations involving toxic minerals. The intent of the article is to make students aware of the dangers so that they may act responsibly in health-related decisions as professional geologists. (Author/SA)

A modification of the Ames test for detecting carcinogens and mutagens using a strain of bacteria is described. A suggestion is given for checking the correctness of procedures by using particular hair dyes which have been shown to be mutogenic. (Author/SA)

Three derivations of the complete discharge time of a capacitor through a resistor are reviewed and examples of potential interest in the classroom are given. (Author/SA)

Presents two demonstrations which are intended for chemistry college students. These demonstrations are: (1) enhancement of concentration quenching by micelles; and (2) the thermite lecture demonstration. (HM)

Traces the history of the search for the ultimate nature of matter. The work of outstanding physicists since the late nineteenth century is discussed as it relates to the total picture of the search for a single unifying theory. (SA)

An inorganic chemistry course at the Free University of Amsterdam is part of an integrated program involving practical work and theoretical study for chemistry students. Twelve experiments are required and 11 are performed by students in groups of fours. (Author/SA)

Describes the use of cassette tape recordings in preparing freshman chemistry students for experiments in laboratories. The tapes are said to have decreased student anxiety in the laboratory and increased laboratory skills. (SA)

Discusses the impact of using laboratory exercises and queries on developing student sensitivity to bioethical issues. Examples of these questions and the responses of students of an introductory life science course at Worcester Polytechnic Institute, Worcester, Massachusetts are presented. (HM)

Describes an elastic Foucault pendulum designed to demonstrate how the rotation of the plane of oscillation depends on geographical latitude, and shows that this rotation vanishes at the equator. (GA)

Describes how to measure Brewster's angle using Polaroid sunglasses and the reflection of the ceiling light on a polished floor. (GA)

In this experiment, the student duplicates the experiment reported by Wohler in 1828. (BB)

In this experiment, benzylic hydrogen reactivity is used to prepare dimers of a variety of alkyl benzenes, and the benzylic hydrogen reactivity of these compounds are compared. (BB)

This simple two-phase procedure for the oxidation of secondary alcohols to ketones is applicable to a wide variety of substrates and is also ideally suited for the undergraduate laboratory. (BB)