Explains the redux chemistry of the experiment of cleaning pennies with a vinegar-salt solution. (Contains 12 references.) (YDS)

Rx values in thin-layer chromatography (TLC) depend strongly on the solvent saturation of the atmosphere above the liquid in the TLC developing chamber. Presents an experiment illustrating the potentially dramatic effects on TLC Rx values of not equilibrating the solvent atmosphere during development. (ASK)

Presents an activity that explores the temperature behavior of UV-sensitive beads and investigates the effectiveness of sunscreens. (ASK)

Contends that chemical education proposals for changing the conception of chemistry literacy should include making explicit the relationship between chemistry as science and chemistry as technology. Illustrates the importance of distinguishing between scientific and technological activities by explaining the events and processes that are…

Examination of senior secondary and tertiary level chemistry students' descriptions of their mental models for chemical bonding revealed prevalent alternative conceptions. Some 20 alternative conceptions were revealed, the most common being belief that continuous ionic or metallic lattices were molecular in nature, and confusion over ionic size…

Grade 10 students in Singapore find qualitative analysis one of the more difficult topics in their external examinations. Fifty-one grade 10 students from three schools were interviewed to investigate their perceptions about learning qualitative analysis. The results showed that students found qualitative analysis tedious and difficult to…

Introduces a demonstration that can be used to explain elementary chemical thermodynamics of heating and boiling. (YDS)

Presents an activity that allows students to apply problem-solving skills and chemical principles to calculate the cost for converting a gasoline-powered vehicle to propane. (Author/ASK)

Describes pigments and artists' colors from a chronological perspective. Explains how chemical analysis can be used to distinguish the differences between artists' palettes, identify the evolution of art, and lead to restoration of an art work. (Contains 13 references.) (YDS)

Taking the recently released Junior Secondary School Chemistry Curriculum (JSSCC) in the People's Republic of China as a case, this paper approaches the issue of how to realize the idea of scientific literacy within a secondary school science curriculum. Subject matter and its companion meanings were used as the framework to explore the embedding…

The background to this study are the difficulties facing the majority of Greek pupils in understanding chemistry concepts and, therefore, performing well in the National Examinations. The aim was to explore the problems and to suggest ways in which the situation might be improved. Working with 105 Greek pupils aged 15 to 16, the first stage of the…

I present a proposal for a laboratory practice to generate and analyze data from a saturation equilibrium binding experiment addressed to advanced undergraduate students. [[superscript 3]H]Quinuclidinyl benzilate is a nonselective muscarinic ligand with very high affinity and very low nonspecific binding to brain membranes, which contain a high…

The process of construction of meanings for the concepts of concentration and neutralization is explored in terms of "contextualizing practices" (Lemke, 1990, "Talking Science. Language, Learning and Values," Norwood, NJ: Ablex) creation of meanings through connections established among actions and their context. This notion is expanded to include…

"Mystery Powders" is a popular exploratory activity in which secondary students describe properties of several white, powdery substances by means of observing their structure through magnifiers or dissection scopes, reactions with a variety of liquids, and heat. Once students or groups have determined the properties of the various powders, they…

Life as people know it here on Earth exchanges energy and materials with the environment. Life forms grow, develop, produce waste products, and reproduce, storing genetic information in DNA and RNA and passing it from one generation to the next. Life evolves, adapting to changes in the environment and changing the environment in return. The basic…