Describes fluorescence experiments demonstrating that emitted light is at longer wavelengths than absorbed light and that fluorescence decays rapidly when the source of excitation is removed. Systems whose acidic and basic forms have different fluorescent characteristics are used to demonstrate fluorescence visible and invisible to the naked eye.…

Background information and procedures are provided for experiments in which the zinc and strontium content in bones (fossils and/or fresh mammalian samples) is analyzed to determine relative amounts of animal and vegetable foods consumed by an individual during its lifetime. (JN)

Points out that excellent results are obtained using an air-natural gas flame in atomic absorption experiments rather than using an air-acetylene flame. Good results are obtained for alkali metals, copper, cadmium, and zinc but not for the alkaline earths since they form refractory oxides. (Author/JN)

Reactions of phenolphthalein with sodium hydroxide and sulfuric are discussed. Also discusses the sulfonation of phenolphthalein, listing experimental results related to the sulfonation reaction. (JN)

Provides background information, procedures, and results of an undergraduate physical chemistry experiment on the polarization of absorption spectra of cyanine dyes in stretched polyvinyl alcohol films. The experiment gives a simple demonstration of the concept of linear dichromism and the validity of the TEM method used in the analyses. (JN)

Three experiments demonstrating the feasibility of encapsulating liquids within a starch matrix are described, including encapsulation of linseed oil using the zanthate method and of turpentine and butylate using the calcium adduct procedure. Encapsulated materials, including pesticides, are slowly released from the resulting matrix. Considers…

Background information, laboratory procedures, and discussion of results are provided for syntheses of cobalt (III) complexes, I-III, illustrating three possible bonding modes of glycine to a metal ion (the complex cations II and III being linkage/geometric isomers). Includes spectrophotometric and potentiometric methods to distinguish among the…

Laboratory procedures, background information, and discussion of experimental results are provided for the preparation of Thallium (I) Pentacyanocobaltate (II). The preparation of this pale green salt is carried out in an aqueous medium. (Author/JN)

Background information, laboratory procedures, and discussion of results are provided for the synthesis and chemiluminescence of adamantylideneadamantane-1,2-dioxetane (I). Results provided were obtained during a normal junior level organic laboratory course. All intermediates and products were identified using routine spectroscopic analysis.…

Background information, laboratory procedures, and discussion of results are provided for experiments designed to familiarize students with the biochemistry of nicotinamide coenzymes and the chemistry involved in their reactions. In addition, students are exposed to ultraviolet (UV)-spectroscopy as a tool for investigating reaction mechanisms in…

This article about science fairs provides a list of topics children can research and suggestions for evaluating the possibilities of project ideas before children invest much work in them. Ideas for selecting a fair date and location, choosing judges, and involving parents and the community are included. (PP)

Information is presented for teaching about the formation of tornadoes and their effects. Ideas for relevant class discussion topics, writing assignments, and experiments to illustrate how temperature and air pressure changes involved in the storms work are also given. (PP)

Describes use of laboratory kits for home-based experimental studies for external science students. Contents of kits and extra equipment the student would need are listed, selection of suitable experiments and arrangements for loan of kits are discussed, and performance of external students using kits is compared to that of internal students. (EAO)

Physicists had assumed that the world is distinguishable from its mirror image and constructed theories to ensure that the corresponding mathematical property (parity) is conserved in all subatomic processes. However, a scientific experiment demonstrated an intrinsic handedness to at least one physical process. The experiment, equipment, and…

Discusses the nature and use of scientific balloons. Topics addressed include: (1) types of balloons; (2) lifting gases; (3) polyethylene balloons; (4) duration of balloon flight; and (5) use of balloons in scientific research. (JN)