Bounded by the statements of Feynman and Galileo, I describe certain tricks that can be useful for the teaching of physics. In particular, I describe the calculation of the center of mass (centroid) of an arc of circumference and a circular sector. For this purpose, I also use Pappus's theorems. An Appendix is available with Archimedes' method to…

The various aspects of projectile motion have been analyzed many times in this journal. As a sample, over the years, authors have investigated particular details of the path of a projectile and different situations for launching projectiles. Others have written about a nifty way to determine the maximum height of a projectile, finding the range of…

One of the greatest challenges in a student's ability to successfully complete reactions in organic chemistry is the ability to differentiate between reactions that have similar structures and proceed through similar reaction mechanisms. Featured in this article is an interleaved reaction review activity called a reaction web. Students are divided…

In this paper, we propose a novel method for deriving Russell-Saunders terms of complex atomic systems with an arbitrary number of equivalent electrons in orbitals with a higher azimuthal number. The method can be regarded as an extension of the classic works of Douglas, McDaniel, and Hyde but with several notable improvements, including the…

By organizing an extracurricular seminar, based on the analysis of the intermolecular dispersion action in normal alkanes, a new topological index (named "Intermolecular Interaction Index (IMI)") was proposed to express the intermolecular dispersion force. The IMI has an excellent linear relationship with the boiling point (T[subscript…

Biochemistry is becoming increasingly crucial for undergraduates majoring in biology, chemistry, agriculture, and medicine. In recent years, much research has been carried out on promoting this course's teaching outcomes. However, the knowledge structure of undergraduate biochemistry teaching research has yet to be formed. Here, 715 validated…

The UV--vis absorption of cyanine dyes is a common experiment in many physical chemistry teaching laboratories. As part of the analysis, students are often asked to hypothesize why the predicted absorption differs from the measured values and why dyes which are predicted to have the same absorption have measured values which differ from each…

In school chemistry, the oxyhydrogen or "Knallgas" reaction is used to provide evidence of hydrogen gas in the squeaky pop test. However, the test actually indicates the presence of an explosive gas mixture of hydrogen and oxygen (oxyhydrogen gas) rather than pure hydrogen. The sheer observations of an explosive reaction and the…

This research is a systematic literature review study that aims to explore the evidence in publications that report on the types of misconceptions experienced by students in learning chemistry by providing types of students' chemical misconceptions based on levels and obtaining the correct formulation of misconceptions so that they can be used as…

The emerging field of genomic medicine offers an opportunity for biology and anatomy teachers to bring the topics of DNA, genetics, molecular processes, and evolution together into one experience. Through the genomic medicine paradigm, students see the unbroken connection between small biological topics such as mutations and their potential…

In nature, we often observe interesting phenomena for which we would like to find a physical explanation. One such phenomenon is presented in this paper.

The Physics Teacher has published over the years many inspiring papers with an historical slant and we agree with Thomas B. Greenslade, who recently wrote that teaching physics is about "integrating physics with human culture.… if we are going to leave a lasting impact on our students, we should do more than teach them pure physics."…

Despite its proven added value, modeling-based learning (MbL) in science is not commonly incorporated into the early grades. Our purpose in this descriptive case study was to enrich our understanding of how kindergarten children enact MbL by examining these children's constructed models and their accompanying oral descriptions of their models. For…

The preparation of ethyl acetoacetate is a distinctive, century-old classic organic chemistry laboratory project. Ethyl acetate and sodium metal (sodium ethoxide) are reacted by Claisen ester condensation to produce the sodium salt of ethyl acetoacetate and then obtain the refined product by acidification as well as washing, drying, and…

DNA-functionalized gold nanoparticles (DNA-AuNPs) have become a popular science theme since their invention in 1990s. They impact our daily lives by playing key roles in rapidly identifying and quantifying important analytes, and are a well-suited chemistry course content for beginners of chemical research. While the salt-aging method represents…