Summarizes chemical principles underlying the operation of automobiles and the cause of air pollution, including concentrations of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen. Comments and opinions are made concerning present and future pollution control devices. (CC)

Summarizes current status of our knowledge about acid-base interactions, including Lewis considerations, experimental design, data about donor-acceptor systems, common misconceptions, and hard-soft acid-base model. Indicates that there is the possibility of developing unifying concepts for chemical reactions of inorganic compounds. (CC)

Briefly describes a number of laboratory and instructional materials that are commerically available and of interest to engineering educators. (JR)

Discusses fundamentals of rainbow formation, including the reflection and dispersion theories underlying primary, secondary and high-order bows. Included is a series of further analytical problems. (CC)

Describes the construction and use of a rotating-room apparatus. The device has a 48-inch diameter platform, seats four at a table, and rotates at four possible speeds. It is easily transported and erected without special arrangements. (Author/MLH)

Derives Kepler's three laws of planetary motion algebraically from conservation principles without introducing Newton's law of force explicitly. This procedure can be presented to students who have had no more than high school algebra. (Author)

Describes an experiment for the undergraduate electricity and magnetism or mechanics laboratory to investigate free and driven oscillations. The RLC circuit is pulsed with a pulse generator when free oscillation is being studied and is driven with a low-impedance sinusoidal generator when driven oscillation is being studied. (Author/MLH)

Describes the use of biofeedback machines in biology classes which provide students with an awareness of their own brain waves and as a device to demonstrate the fact that the body responds readily to the mind. (BR)

Presents an alternative series of investigations replacing the propanone-trichloromethane system (Topic 10) in the Nuffield A-Level course. A trichloromethane-ethyl ethanoate (acetate) system presented in four experiments give good results and removed the dangers arising from the other system. Topic 10 need not be re-written, just the replacement…

Presents part of a new series aimed at providing exploratory activities for preschool children as they seek to become acquainted with the world in which they live. (Author/EB)

Describes construction and use of a simple auxanometer which students can use to accurately measure root growth rates of intact seedlings. Typical time course data are presented for the effect of ethylene and indole acetic acid on pea root growth. (Author/BR)