The objective of this manual is to provide a set of basic analytical procedures commonly used to determine environmental quality. Procedures are designed to be used in an introductory course in environmental science and are explicit enough to allow them to be performed by both the non-science or beginning science student. Stressing ecology and…

An activity in which students combine physical and mathematical principles in a measurement situation is described. (SD)

A gas pressure gauge has been constructed for use in a student experiment involving the law of atmospheres. From pressure data obtained at selected elevations the average mass of air molecules is determined and compared to that calculated from the molecular weights and percentages of constituents to the air. (Author/BB)

Exercises are presented for classification of marine algae on the basis of biochemical characteristics such as pigmentation, cell wall components, and food storage products. (BB)

Establishes the extent to which practical work in South African high schools varies with respect to factors such as gender of student, type of school, medium of instruction, and examination board. Investigates the relationship between experience of experimental work and pupil attainment as measured by matriculation grade. (Author/GA)

This experiment uses a nine-chambered plexiglas unit to facilitate rapid construction of galvanic cells and measurement of cell voltage. Using this procedure, a pair of students can construct and obtain the cell voltages of two precipitation cells, three concentration cells, and six redox cells in 30-40 minutes. (BB)

The observation of soap bubbles in a beaker of carbon dioxide gas helps students to feel the pleasure that comes from understanding nature, from applying that understanding to real problems, and from making unexpected discoveries that yield to analysis. (Author/BB)

Describes the apparatus and procedures for conducting a simple speed of light experiment in an average laboratory using a laser source, a rotating mirror, and an oscilloscope. (SL)

Light-emitting diodes (LEDs) are described and three classroom experiments are given, one to prove the, low power requirements and efficiency of LEDs, an LED on-off detector circuit, and the third an LED photoelectric smoke detector. (BB)

Describes a method of recording galvanometer deflections when using a d'Arsonval galvanometer to demonstrate forced, damped simple harmonic motion. (SL)

Smaller amounts of materials are used in organic chemistry experiments as a means of improving air quality in the laboratory. Outlines benefits from this approach and describes two representative experiments in detail. These experiments are the Cannizzaro reaction and preparation of an aromatic nitrile. (JN)

Two demonstrations are described. The first (useful as an introduction to kinetics) shows how the rate of a reaction is fast at first and then gradually decreases to zero when one reactant has been used up. The second is a gas density demonstration using 1,1,2-trichloro-1,2,2-trifluoro ethane. (JN)

Outlines a laboratory exercise that makes use of Beer's Law plots of cysteine constructed at several pH values over a broad range of wavelengths to estimate the tautomeric ratio (R) of two singly charged ionic forms, calculate the microscopic constants, and construct ultraviolet spectra for both light absorbing species. (CW)

Discusses the possibilities of toxins present in medicinal herbs. Describes an experiment in which toxic constituents can be selectively detected by thin-layer chromatography and NMR spectroscopy. (TW)

Describes a comparison of scale of laboratory with respect to time efficiency. Compared full scale and one-tenth scale Grignard reactions with full scale averaging 330 minutes to completion and scaled-down averaging 204. Savings are seen in air pollution, toxicity, solvent cost, and time. (JM)