A diffusion cell to model the permeation of salicylate drugs through the skin using low-cost materials and a sensitive colorimetric analytical technique is described. The diffusion apparatus has been used at a further education college by a student for her AS-level Extended Project to investigate the permeation rates of salicylic acid…

Discusses symmetry elements of molecules, symmetry operations, and point groups. Gives ten examples of assigning a point group to a molecule. (MLH)

Schematically depicts the variety of uses the mole concept has for 0-level chemistry. (CP)

Describes the use of disc or ring magnets magetized axially and iron discs, in conjunction with an overhead projector, as a model of nuclear structure and of complete molecules. (GS)

A laboratory experiment is described which presents some molecular parameters of iodine molecule by studying iodine spectrum. Points out this experiment can be conducted by sixth form students in high school laboratories. (PS)

The ideas behind electrophilic addition to alkenes, and electrophilic substitution in benzene derivatives are discussed. Teaching these concepts to secondary school students is stressed. Five main points useful at this age level are summarized. (Author/CW)

Suggests two methods of developing the study of the noble gases: first, the discovery of the elements and recent discovery of xenon show the human face of chemistry (historical development); second, the properties of noble gas compounds (particularly xenon) can be used to test the framework of conventional chemistry. (Author/JM)

Describes the formation, chemical structure, and several uses of coal. The history of coal usage, production processes, coal tar products, and production of petroleum and other hydrocarbons from coal are also described. (DS)

Describes phase transition in solids and shows how soap films can be used to demonstrate this phenomenon. (Author/SK)

Describes a British secondary school's use of a spectrometer to identify minerals. Discusses the origins of mineral spectra, the preparation of the specimen, the actual spectroscopic scanning, and the interpretation of the spectra. (TW)