In this paper, we show a laboratory experience describing the possibility to build a sensor using a coil to measure small thicknesses of materials with the possibility of measuring temperature simultaneously, with the same built sensor. Its operation is based on the following facts: An electric current (a.c), flows through a coil and a magnetic…

We report on a simple, rapid, and room-temperature undergraduate-level experiment for gold nanoparticle synthesis, analysis, and utilization as a catalyst for the sodium-borohydride-assisted reduction of methylene blue and Congo red dyes. Typical procedures toward gold nanoparticle formation require an elaborate, lengthy synthesis (some requiring…

The concept of equilibrium vapor pressure plays a key role in the general chemistry curriculum; it is among the first and most easily demonstrated examples of equilibrium and frequently caps off the first semester of general chemistry where it illustrates the properties of liquids and intermolecular forces. We report here simple modifications of…

All-solid-state polymer electrolytes (SPEs) have been regarded as an advisible alternative for simultaneously overcoming the safety issues and high energy density demands presented in traditional lithium batteries, and they represent the development orientation of energy storage devices. This course describes the preparation of a cross-linked and…

Secondary metabolite compounds contained in each plant genus have certain characteristics, which is true also of the flavonoid in the genus "Artocarpus." In the experiment described here, third-year undergraduate students performed the isolation and characterization of cycloartocarpin from the roots of "Artocarpus altilis"…

According to the definition, surface tension could be affected not only by intermolecular interaction but also by molecular area. However, in chemistry textbooks, surface tension is mainly explained only in terms of intermolecular interaction. Although the existing surface tension concept in the textbooks can lead to a variety of counterexamples,…

A classic undergraduate introductory experiment is to measure the diffraction and interference pattern from single and double slits to determine slit width and separation. Studies show that Course-based Undergraduate Research Experiences (CUREs) can make science more inclusive when offered at the undergraduate level. Additionally, CUREs help…

A laboratory exercise for the synthesis of a sulfonated styrene-"co"-maleic anhydride polymer and its application as a stain blocker on nylon-6,10, is described. The effectiveness of the sulfonated polymer to prevent the conjugate base of an acid dye from staining the polyamide is demonstrated. This experiment is designed for…

To study the absorption of ultrasound in plexiglas we propose to use gadgets that are available to each student: an ultrasound humidifier, a liquid crystal display of a pad, a polaroid analyzer, a digital camera, a multimeter with thermocouple, and a stopwatch. These devices allow us to visualize a region in plexiglas where ultrasound is absorbed…

Although teaching laboratories offer students the opportunity to act and think like chemists, in many cases students simply follow written procedures to generate predetermined outcomes. In recent years, there has been a movement toward inquiry-, problem-, and discovery-based learning. In a similar vein, the first-semester introductory organic…

Newton's law of cooling describes an object whose temperature decreases exponentially with time. Because of its many applications, it is a frequent topic of introductory physics labs. In this article, I describe an experiment designed for the freshman year algebra-based physics course that applies this law to answering the question, "Why…

"N"-Formamides are important intermediates in the synthesis of many pharmacologically active compounds and are used as protecting groups for amines or as catalysts in different reactions. The current "N"-formylation experiment is designed as a part of an introductory organic chemistry course for undergraduate students. The…

Perturbation of gene expression using RNA interference (RNAi) or CRISPR interference (CRISPRi) is a useful strategy to explore the function of essential genes. In the archaeon "Haloferax volcanii," the CRISPR-Cas system has been adapted as a CRISPRi tool to silence the expression of specific genes. We developed a laboratory class (LC) to…

Although medical students learn human anatomy within a social network of friends/classmates, limited research has examined how social network structure is related to student's performance in human anatomy examinations. This study aimed to examine the association between centrality (i.e., the degree to which a student is connected to other students…

Previous work has highlighted the difficulties students have when explaining wave behavior. We present an investigation of chemistry students' understanding of the double-slit experiment, where students were asked to explain a series of PhET simulations illustrating a single continuous light source, single-slit diffraction, and double-slit…