High school students and students in the first years of college have difficulties in understanding the topic of stoichiometry and, in particular, the concept of limiting reactant. Proposals aimed at overcoming these learning obstacles tend to focus on analogies, and there are few sequences that approach teaching from an experimental perspective.…

Although diffusion is the subject of beginning chemistry classes, there are a variety of experiments, such as the spread of perfume in the classroom, that are often "incorrectly" explained by diffusion alone. To eliminate this common misconception, a recently published method is modified to determine the diffusion constant of hydrogen…

This study describes the process of developing a high-impact, low-cost, and low-maintenance air ventilation system for anatomy facilities. It employed the strategic application of Value Engineering (VE), assuring that the air ventilation system meets contemporary threshold limit values (TLVs) for formaldehyde in the working zone of dissection…

Practical work in optics is essential to understand complex abstract phenomena. Consequently, hands-on experiments are part of most physics' curricula, despite the fact that they can be hard to set up and maintain. In this article, we present a virtual laboratory tool, called SHIRE, which allows students to carry out optical experiments from a…

This study aims to facilitate and implement inquiry-based exercises in the domain of hydrostatic pressure within the subject of physics education. The design research method was used to support eighth-grade pupils at Palembang State Middle School by developing inquiry-based activities on hydrostatic pressure. Three stages--experimental…

After a time away from the classrooms and laboratories due to the global pandemic, the return to teaching activities during the semester represented a challenge to both teachers and students. Our particular situation in a Microbial Physiology course was the necessity of imparting in shorter time, laboratory practices that usually take longer. This…

Outreach science labs aim to promote students' interest. Previous research has often suggested that performing experiments in such labs has a positive effect on their interest. However, these studies often lack a comparison to the effects of performing them at school. This research gap was addressed in the present study. The sample consisted of…

Liquid metals are widely applied in various fields, including chemistry, catalysis, energy storage, chemical sensing, and stretchable electronics, due to their unique deformabilities. However, their behavior under a rod or ring electrode has never been analyzed. Furthermore, research on the deformation behavior of eutectic Ga--In (EGaIn), the most…

Herein we describe an accessible and safe at-home experiment to separate lycopene from tomatoes via liquid-liquid extraction. As a qualitative experiment, it is a canonically elementary instance for high school students to digest the conception of miscibility, immiscibility, and density difference of the two solvents. This experiment was performed…

The activity proposed in this study aims to investigate the equilibrium between the liquid and vapor phases in a mixture of water and acetic acid, both of which are volatile substances. High school students can easily determine the composition of the liquid phase and its corresponding vapor phase at equilibrium using a simple and conceptually…

George M. Hopkins (1842-1902) wrote a series of articles on demonstrating physical phenomena in the "Scientific American" during the last years of the 19th century. These were collected in a book, "Experimental Science," that was first published in 1890, with revisions in 1892 and 1902. It must have been well received, for the…

The family resemblance approach to nature of science is receiving increasing attention by science educators since its inception about a decade ago. Many scholars of science education have contributed and continue to contribute to it not only theoretically but also by applying it empirically to a wide range of areas such as curriculum and textbook…

Ethanol (EtOH) is among the most consumed drugs in the world. The behavior of humans after ingestion of this drug is characteristic: At low doses it may be excitatory and at higher doses, it may induce depressant/sedative effects. Similar effects are observed in the zebrafish experimental model ("Danio rerio"), which has about 70%…

The helium-plasma (HePI) ionization mass spectrometry method was used to track the formation of reaction products and consumption of reactants by continually monitoring the vapors in the reaction headspace in real time. Two examples of the application procedure are presented here: a nucleophilic acyl substitution reaction and a 1,4-nucleophilic…

An introductory experimental course to teach and assess basic organic synthesis and identification skills has been designed. The first work of this course, which is based on the well-known hydrazone formation reaction of benzaldehydes with Brady's reagent, is presented. The designed experiment has many advantages and perfectly matches the goal of…