Diffusion is a fundamental phenomenon that is vital in many chemical processes such as mass transport in living cells, corrosion, and separations. We describe a simple undergraduate-level experiment based on Weiner's Method to probe diffusion in a ternary aqueous mixture of small molecular-weight molecules. As an illustration, the experiment…

Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…

Three plain mirrors, perpendicular to each other, reflect a beam of light back into the direction it came from. An activity is suggested where pupils can employ this feature of perpendicular mirrors and make their own corner cube retroreflector--a kind of cat's eye. (Contains 7 figures and 1 footnote.)

Engaging students in authentic scientific research has become an important component of undergraduate science education at many institutions. The purpose of this paper is to explore authentic research experiences as contexts for learning. The authors review empirical studies of undergraduate research experiences in order to critically evaluate the…

Learning progressions (LPs)--descriptive continuums of how students develop and demonstrate more sophisticated understanding over time--have become an increasingly important tool in today's science classrooms. Here the author discusses some of the research behind learning progressions and presents The Science Inquiry Profile for PreK-4. This is a…

In this paper we discuss the results of an investigation aiming at mapping the conceptions of nature of protestant biology preservice teachers in a Brazilian university, State University of Feira de Santana, and elucidating their strategies to manage the coexistence of scientific and religious knowledge. We employ naturalistic semi-structured…

Part I. The design and development of organic second-order nonlinear optical (NLO) materials have attracted much interest due to their applications in optoelectronic devices and modern communications technology. Donor-pi-acceptor compounds, D-(CH=CH)[subscript n]-A, often exhibit hyperpolarizability that results in laser frequency doubling (second…

The purpose of this study was to determine which of three competing models will provide, reliable, interpretable, and responsive measures of elementary students' understanding of the nature of science (NOS). The Nature of Science Instrument-Elementary (NOSI-E), a 28-item Rasch-based instrument, was used to assess students' NOS…

The nature of knowledge needed for teaching elementary science and the development of such knowledge is a focus of ongoing research in science education. Internationally, there is a move to include scientific literacy as an aim of science education curricula. In order to teach such curricula teachers need two types of subject matter knowledge…

Understanding of NOS (nature of science) appears as a prerequisite of a scientifically literate person. Promoting adequate understanding of NOS in pre-service physics teachers is, therefore, an important task of science educators. Before doing that, science educators must have information concerning their pre-service teachers' conceptions of NOS.…

This study investigated whether participation in the Partnership for Research and Education in Plants (PREP), a long-term authentic plant research project, in conjunction with explicit verses implicit instruction can change high school students' conceptions of the nature of science (NOS). The participants included a total of 134 students comprised…

With funding from the United States National Science Foundation, 30 historical short stories designed to teach science content and draw students' attention to the nature of science (NOS) have been created for post-secondary introductory astronomy, biology, chemistry, geology, and physics courses. The project rationale, story development and…

A number of studies have already investigated children's stereotypical images of scientists as being male, old, bald, wearing eyeglasses, working in laboratories, and so forth. There have also been some interventions to impose more realistic images of scientists. In this study, a science camp was conducted in Turkey with a team of scientists…

Due to the growing number of students from populations underrepresented in the sciences, there is an intensified need to consider alternatives to traditional science instruction. Inquiry-based instructional approaches provide promise and possibility for engaging underrepresented students in the activities of science. However, inquiry-based…

This mixed-methods investigation compared the relative impacts of instructional approach and context of nature of science instruction on preservice elementary teachers' understandings. The sample consisted of 75 preservice teachers enrolled in four sections of an elementary science methods course. Independent variables included instructional…