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 virtual reality (VR) session was introduced to an advanced inorganic chemistry class, a class available to junior and senior undergraduate students at the University of California, Los Angeles. The VR session helped the students to learn complicated aspects of metal coordination chemistry and molecular orbitals via an immersive three-dimensional…

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…

The purpose of this study is to develop a thinking process model that reveals cognitive bias through analyzing students' cognitive biases in processing experimental manuals. Twenty-two college students participated in the study. During the "making electromagnets" experimental activity, we collected students' concurrent verbal protocols,…

Proteins must interact with a variety of other cellular components to properly perform their functions. We have developed a series of five experiments based on the robust bacterial single-stranded DNA binding protein (SSB) to characterize both known and unknown protein-protein and protein-DNA interactions. Students work in groups to generate and…

For many years, Atwood's machine has been used to demonstrate, illustrate, or verify Newton's laws in introductory physics courses. It consists of two objects of different mass that are fastened to the ends of a string that hangs over a pulley. In an idealized situation, one assumes that pulley friction, the string's mass, and changes in the…

To date, the efficacy of virtual experiments is not well-understood. To better understand what differences may exist between a hands-on learning environment and a virtual learning environment, three experiments were chosen for investigation. For each experiment, approximately half of the students completed a hands-on version of the experiment, and…

Toys are designed to be fun and playful and are highly motivating for both children and adults. Commercial toys and child-designed toys can be used both in the classroom and at home to encourage creativity and to teach science concepts. Much of what children can do with toys involves tinkering, defined by Merriam Webster as "to repair,…

Science demonstrations are a simple, cost-effective method of improving interest in STEM and highlighting the diversity of scientists, which can impact audience members' sense of belonging and, in turn, influence self-efficacy. However, the pedagogy of science demonstrations has been criticized as creating a power imbalance between the presenter…