An undergraduate experiment for the organic laboratory is described that utilizes microwave heating to prepare 5- substituted 1H-tetrazole derivatives through a (3 + 2) cycloaddition between aryl nitriles and sodium azide. The reaction mixture is analyzed by thin layer chromatography. The products are purified through an acid-base extraction and…

This paper describes an undergraduate laboratory experiment where students study the heating behavior of magnetic nanoparticles in the presence of alternating magnetic fields. Average score on the post-test was 45±12% for students who completed the lab online, versus 43±11% for those doing the activity hands-on. Post-test scores were significantly…

Practicing chemists use models, diagrams, symbols, and figures to represent phenomena which cannot be detected by the human senses. Although research suggests that these external representations (ERs) can also be used to address the challenges that students have in learning chemistry, it is not clear how instructors' use of ERs aligns with their…

A simple synthesis of fluorescent carbon quantum dots from lemon juice is described to introduce advanced high-school students and undergraduate college students to nanoparticle synthesis and quantum dots. The synthesis is based on the carbonization of lemon juice using only a hot plate stirrer. Column chromatography is used to separate different…

When sound waves are taught at the secondary level, the speed of propagation of sound is one of the most important characteristics to be analyzed. However, it is very common in textbooks that the value of sound speed in air is considered constant regardless of the experimental conditions. The great question is that since sound is a mechanical…

Practical skills in science education, defined as those developed through the observation, demonstration, manipulation, and application of scientific principles, valued in both academia and industry, feature conspicuously in curriculums the world over. Efficiently imparting such skills to students necessitates access to scientific equipment of…

Through the experiments described in this article, students become acquainted with the principles behind ternary liquid-liquid systems and/or Aqueous Two-Phase Systems (ATPS), and their characterization by the determination of the binodal curve, tie-lines, tie-line lengths and critical point, as well as in applying the non-random two-liquid model…

Comfort whilst camping overnight during outdoor pursuits is based on pain free and warm sleeping arrangements and is highly dependent on the performance of the sleeping bag and sleeping mat. In adventurous and challenging situations, performance can contribute to safety and expedition success. From the manufacturer's point of view, thermal…

Self-regulation is an active and constructive process in which students regulate and observe their own behaviour, motivations and cognition by setting their own goals during their learning process. In this study, the aim is to investigate the effects of biology laboratory practices that are supported by self-regulated learning strategies on…

A guided inquiry-based experiment exploring the regioselectivity of the hydration of phenylacetylene is described. The experiment uses an acidic gold(III) catalyst in a benign methanol/water solvent system to introduce students to alkyne chemistry and key principles of green chemistry. The experiment can be easily completed in approximately 2 h,…

The characteristics of the inner layer of the atmosphere, the troposphere, are determinant for Earth's life. In this experience we explore the first hundreds of meters using a smartphone mounted on a quadcopter. Both the altitude and the pressure are obtained using the smartphone's sensors. We complement these measures with data collected from the…

Could Usain Bolt achieve what teachers often fail to do? Could this famous Olympic winner challenge and motivate students to study mechanics and introduce them to the principles of physics in a fun way, outside of the classroom? In order to answer these questions, we "invited" for one semester the world record holder to visit our Greek…

The classroom jumping ring demonstration is nearly always performed using alternating current (AC), in which the ring jumps or flies off the extended iron core when the switch is closed. The ring jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant…

"Catalase," an enzyme found in both plant and animal cells, prevents the accumulation of toxic levels of hydrogen peroxide (H[subscript 2]O[subscript 2]) by catalyzing its decomposition to water and oxygen gas. Because this enzyme is ubiquitous, it is frequently used in high school biology laboratories to explore enzyme reactions. This…

I describe an easy-to-build instrument for illustrating the Lorentz force and measuring magnetic fields in introductory physics labs.