An experiment is described that allows students to experimentally determine an empirical formula for silver sulfide. At elevated temperatures, silver sulfide reacts in air to form silver, silver sulfate, and sulfur dioxide. At higher temperatures (960 [degree]C) silver sulfate decomposes to produce metallic silver. (Contains 1 figure and 1 table.)

In this laboratory experiment, general chemistry students measure the heating curves for three different systems: (i) 500 g of room-temperature water heated by a small desk lamp, (ii) 500 g of an ice-water mixture warmed by conduction with room-temperature surroundings, and (iii) 500 g of an ice-water mixture heated by a small desk lamp and by…

Degradative enzymes in over-the-counter products from pharmacies and health food stores provide good examples of biological catalysis. These include [beta]-galactosidase in Lactaid[TM], [alpha]-galactosidase in Beano[R], [alpha]-amylase and proteases in digestive aids, and proteases in contact lens cleaners. These enzymes can be studied…

The use of generated intensity distributions as overlays on the HCl rotational-vibrational FTIR spectrum is presented as an effective method to integrate lab work into the physical chemistry lecture. The overlays that best match the actual HCl spectrum are generated using a pre-exponential factor of 2J+2.

Volume phase holographic (VPH) optical elements have made a major contribution to Raman spectroscopy by providing notch filters, and VPH gratings that provide remarkable performance advantages over previous technologies. Holographic notch filters have eliminated Rayleigh scattered laser light from single monochromators, thereby contributing to the…

A laboratory experiment was conducted in which the students synthesized yellow colloidal silver, estimate particle size using visible spectroscopy and studied aggregation effects. The students were thus introduced to nanotechnology along with other topics such as redox chemistry, limiting and excess reactants, spectroscopy and atomic size.

A green laser pointer could be used in a flashy demonstration of laser-induced fluorescence in the gas phase by directing the beam of the laser through a cell containing [I[subscript]2] at its room temperature vapor pressure. The experiment could be used to provide valuable insight into the requirements for laser-induced fluorescence (LIF) and the…

Traditional modes of chemistry education in schools focus on imparting chemistry knowledge to students via instruction. Consequently, students often acquire the mistaken understanding that scientific knowledge comprises a fixed body of "proven" facts. They fail to comprehend that the construction of scientific understanding is a human…

Designed for high school science teachers, the document warns of potential health threats of performing certain experiments and using certain chemicals or chemical combinations in their courses. Following a rationale for more carefully considering health dangers, the document gives suggestions on what can be done by teachers. Reports such as a…

This report by the Automation in the Medical Sciences Review Committee of the National Institute of General Medical Sciences, National Institutes of Health, assesses the current status of medical laboratory science and identifies specific areas in need of further development. (CS)

A three-year research effort was conducted to design a crime laboratory proficiency testing program encompassing the United States. The objectives were to: (1) determine the feasibility of preparation and distribution of different classes of physical evidence; (2) assess the accuracy of criminalistics laboratories in the processing of selected…

THIS REPORT PRESENTS A BRIEF, NONTECHNICAL, PICTORIAL OVERVIEW OF THE EDUCATIONAL POTENTIAL AND APPROXIMATE COST TO CERTAIN CONFIGURATIONS OF ELECTRONIC AUDIO, AUDIO-VISUAL, AND TELEVISION TEACHING SYSTEMS. EQUIPMENT IS CATEGORIZED ACCORDING TO THE EXTENT TO WHICH PROGRESSIVE MODES OF LEARNING ARE SERVED, THE NATURE AND COMPLEXITY OF THE HARDWARE…

Designed to accompany the student text on the nervous system, this manual presents laboratory activities dealing with concepts presented in the text. Thirty-seven activities are described. Four supplementary activities dealing with concepts in electricity are also included. Laboratory activities are divided into several parts, each part covering a…

A comprehensive checklist is presented for assistance in planning and remodeling all types of industrial arts facilities. Items to be rated are in the form of suggestions or specifications related to facility function. Categories developed include--(1) purpose, (2) general laboratory arrangement, (3) hand tools and storage, (4) room safety, (5)…

LANGUAGE LABORATORIES HAVE CHANGED FROM SIMPLE INSTALLATIONS, EQUIPPED WITH RECORD PLAYERS OR TAPE RECORDERS, TO COMPLEX INSTALLATIONS WITH FACILITIES FOR SELF-INSTRUCTION, DIAL SELECTION OF AUDIO PROGRAMS, REMOTE STORAGE OF TAPES, AND EVEN RECEPTION OF TV. LANGUAGE LABORATORIES OF THE FUTURE MUST HAVE THE CAPABILITY OF BEING OPERATED EFFICIENTLY…