The study describes the Lewis structure representation of various free radicals, which are quite similar to the ClO radical and its isoelectronic analogues. The analysis of the periodic trends of these radicals shows that oxygen is the most electronegative atom among them.

Different formulations of thermodynamic work "w" as a pressure-volume integral are examined for a piston moving against a gas in an irreversible process. Proper expressions are obtained using the instantaneous pressure of the gas on the piston as the integrand and also using certain external pressures as the integrand. There are two common yet…

This article describes an undergraduate analytical chemistry experiment developed to teach instrumental lab skills while incorporating common interferents encountered in the real-world analysis of catechol. The lab technique incorporates potentiometric-flow injection analysis on a dibenzo-18-crown-6 dual platinum electrode to detect catechol in…

The students prepare tea samples using different quantities of lemon balm leaves ("Melissa officinalis") and measure the rosmarinic acid contents by an HPLC-DAD method. The antioxidant properties of the tea samples are evaluated by a spectrophotometric method using a radical-scavenging assay with DPPH. (2,2-diphenyl-1-picrylhydrazyl). Finally the…

Two concept maps have been developed to represent the organization of the material in a first-semester general chemistry course into two overall themes: a structure and properties theme and a quantitative chemical relationships theme. By providing these maps to students and referring to them in class, it is hoped that the instructor can assist…

These laboratory experiments are designed to explore aspects of nanoscale chemistry by constructing and spectroscopically analyzing thin films of photonic crystals. Films comprised of colloidal spheres and polydimethylsiloxane exhibit diffraction-based stop bands that shift reversibly upon exposure to some common solvents. Topics covered in these…

The ability to sequence genes has vastly altered our understanding of higher-level relationships among organisms such as those found at the kingdom level. It is important for biology teachers to incorporate these new views and not retain outdated concepts still present in some textbooks. This article provides an overview of our new understanding…

The development of a new low-cost, six-electrode instrument for measuring the electrical properties of the self-assembled monolayers of gold particles is being described. The system can also be used to measure conductive liquids, except for those that contain aqua region.

The Reaction-Map of Organic Chemistry lists all the most commonly studied reactions in organic chemistry on one page. The discussed Reaction-Map will act as another learning aide for the students, making the study of organic chemistry much easier.

Students whose high school biology course included evolution but not creationism knew more about evolution when they entered college than did students whose courses included evolution plus creationism or whose courses included neither evolution nor creationism. Similarly, students who believed that their high school biology classes were the…

The plasma membrane is the membrane that serves as a boundary between the interior of a cell and its extracellular environment. Lipid rafts are microdomains within a cellular membrane that possess decreased fluidity due to the presence of cholesterol, glycolipids, and phospholipids containing longer fatty acids. These domains are involved in many…

Several teaching approaches with a focus on active learning have been developed in the past, with the aim to encourage the learner to take responsibility for their own learning progress. Most of these approaches augment the learning of material after it was introduced in conventional lectures. The aim of this project was to develop a teaching…

The aim of this study was to investigate whether, in the Hong Kong context, self- and peer-assessment promote students' self-reflection and enable students to understand their own strengths and weaknesses better. A three-stage assessment strategy was employed in three Science courses at The Chinese University of Hong Kong: (1) students developing…

For many students, the conceptual learning of quantum mechanics can be rather painful owing to the counter-intuitive nature of quantum phenomena. In order to enhance students' understanding of the odd behaviour of photons and electrons, we introduce a computational simulation of the Mach-Zehnder interferometer, developed by our research group. An…

Two studies analyzed impacts of writing and receiving web-mediated peer reviews on revision of research reports by undergraduate science students. After conducting toxicology experiments, 77 students posted draft reports and exchanged double-blind reviews. The first study randomly assigned students to four groups representing full, partial, or no…