Natural experiments are often used for answering research questions in which randomization is implausible. Effective recruitment strategies are well documented for observational cohort studies and clinical trials, unlike recruitment methods for time-sensitive natural experiments. In this time-sensitive study of the impact of a minimum wage policy,…

Electromagnetism is a complex topic for students at different educational levels. Perhaps one of the reasons for this is that students are unable to visualize the forces, fields, currents, and other electromagnetism key concepts that are related to the topic. Most teachers address this difficulty by including the use of some technological…

The Young's two-slits experiment is arguably one of the most famous and beautiful experiments in physics. In introductory physics labs the experiment is almost exclusively carried out using a laser, and it is introduced this way in some introductory physics textbooks. In the case of laser illumination, light passes directly through the slits and…

An experiment is described where a billiard ball and a golf ball were projected with backspin on a horizontal surface to measure the transition from sliding to rolling. During both phases, the torque on the ball is affected by an offset in the line of action of the normal reaction force.

A new experiment for use in introductory nanotechnology courses is described. This experiment allows students to fabricate metallic wires with microscale lateral dimensions and nanoscale vertical dimensions. Fabrication occurs in the capillaries of polydimethylsiloxane (PDMS) stamps modified with hydrophilic polymers. This experiment provides…

To understand the ways that manipulatives might support changes in students' reasoning about algebraic generalizations, a constructivist teaching experiment was conducted with two sixth-grade students. The students interpreted numerical situations with units of one and could construct units of units in mental activity. Initially, the students'…

A set of inexpensive and pedagogically rich experiments focusing on S[subscript N]1, E1, and E2 reactions have been updated to include modern computational and spectroscopic analyses. The S[subscript N]1 experiment involves treatment of "tert"-amyl alcohol with hydrochloric acid to generate the corresponding alkyl chloride, which is used…

A laboratory experiment that involves the synthesis, characterization, and application exploration of a metal-organic framework (MOF) has been developed for first-year undergraduates in the Faculty of Engineering at National University of Singapore. The desired MOF material was prepared from commercially available reagents in a facile…

Biodiesel is an important biomass, largely employed in the transport sector and produced from vegetable oils. Additionally, waste cooking oils may be reused to produce biodiesel fuel, minimizing environmental pollution. A laboratory experiment that affords a widespread way to discuss degradation concepts and tools for used vegetable oil…

When injecting dye into a vortex, one finds that the dye remains captured around the vortex core over minutes, despite the fact that the vortex (and the dyed region) is strongly time-dependent. According to a recent theory, three-dimensional time-dependent vortices should be defined as rotating, material-holding regions of the fluid. Vortices…

Carbohydrates are an essential group of molecules to the organic chemistry classroom providing molecular relevance to a common ingredient in chemical biology. While the meticulous elucidation of the carbohydrate structures by Fischer and others is an engaging topic in the lecture, there are few laboratory experiments that can emulate carbohydrate…

A continuous flow photopinacol coupling of benzophenone has been developed and implemented in the undergraduate laboratory. This photoreduction was accomplished using 2-propanol as an H atom donor and cosolvent in the reaction. The simple and inexpensive UV light source and flow reactor design (less than $350/photochemical flow system) provide an…

Williamson ether experiments are commonly performed by students in undergraduate organic chemistry instructional laboratory courses. In this multioutcome experiment, students were provided 4-bromophenol and one of three alkyl halides: 1-bromopentane, 1-bromobutane, or 1-bromo-3-methylbutane. The alkyl halides served as the unknown component of the…

An undergraduate organic chemistry experiment has been developed that features asymmetric synthesis of an enantioenriched secondary alcohol, followed by determination of its absolute configuration using the competing enantioselective conversion (CEC) method. Students are given a ketone and an unknown enantiomer of CBS (Corey-Bakshi-Shibata)…

Virtual laboratories have started to be the leading alternative teaching tools during the COVID-19 pandemic process. The "Acid-Base" subject is among those that form the foundations of biochemistry. Students can learn the "Acid-Base" subject in a secure environment, with remote access through the use of virtual laboratory…