Water chemistry is central to aquarium design, and it provides many potential applications for discussion in undergraduate chemistry and engineering courses. Marine aquaria and their life support systems feature many chemical processes. A life support system consists of the entire recirculation system, as well as the habitat tank and all ancillary…

Within the historical context of the development of chemistry, Avogadro's hypothesis represents a fundamental concept: It allowed Avogadro to explain Gay-Lussac's law of combining volumes and it allowed Cannizzaro to establish a more accurate set of atomic mass values. If students are going to understand the concept of relative atomic masses and…

Investigates high school students' understanding of the physical relationship of chromosomes and genes as expressed in their conceptual models and in their ability to manipulate the models to explain solutions to dihybrid cross problems. Describes three typical models and three students' reasoning processes. Discusses four implications. (YP)

Reports that young children in the pedestrian accident prone age range of four-eight years hold a variety of naive conceptions regarding speed. Proposes a primary science unit using a conceptual change approach. (MVL)

The process of conceptual change, in learners and in scientific knowledge, indicates that: (1) change involves complex and varied commitments to methods of investigation, aims and goals of investigation, and prior knowledge; (2) change leads to consensus forming or dissensus forming activities; (3) knowledge claims and procedures for testing…