Systems thinking is highly desirable for re-imagining chemistry education, which will help in the development of an integrated and sustainable approach that takes into account the interdependence of a system under study with other components of the ecosystem rather than practicing a fragmented approach. Thus, to develop a systems' perspective into…

A phone emitting sound of a fixed frequency is sliding on an inclined plane and approaching a second phone kept at the bottom of the plane. The detected frequency versus time data by the second phone are used to calculate the acceleration of the sliding phone. The primary objective of this paper is to calculate the sliding friction between the…

We propose a semiquantitative experiment that associates video-analysis and ordinary procedures of experimental physics whose objective is to investigate the dual character of Oobleck, a mixture of cornstarch in water, which appears thicker or thinner depending on how it is physically manipulated. The results are presented and interpreted taking…

This paper describes an upper-division undergraduate exercise involving the synthesis and iodometric and infrared spectroscopic analysis of the peroxide double salt [Zn(NH[subscript 3])[subscript 4]][Mo(O[subscript 2])[subscript 4]]. Here, iodometric methods are employed to determine the peroxide content of the compound, a procedure widely used…

This paper describes a first-year undergraduate exercise involving the synthesis of an "unknown" polyiodide salt, (NMe[subscript 4])[I[subscript 5]], and the determination of its formula using the classic iodine-thiosulfate (iodometric) titration. The exercise introduces students to simple synthetic and titrimetric techniques, assists…

The acoustic resonance in four glass Helmholtz resonators with diameters of 70, 52, 40, and 32 mm was detected in the frequency range of 360 to 1700 Hz using the simple experimental setup presented in this paper. The measured amplitudes of acoustic pressure required correction since the sound pressure amplitude of the loudspeaker used was not…

When we teach thermodynamics, a vacuum container used to keep food isolated from air is a cheap and interesting teaching device. There are some experiments already described in the literature and we can also find videos of demonstrations on YouTube. At the same time, there is increasing interest in how to utilize smartphones in physics…

This paper addresses a popular topic in science teaching and competitions for primary and secondary school students. Experiments with colliding coins are relatively easy to perform and therefore popular in science lessons. We used the idea in the science competition we organized for pupils aged 6 to 13 years.7 The science competition is based on a…

DNA structure has been leveraged in a variety of facets that allow scientists to perform a range of assays, including ones for identification of species, establishing evolutionary relationships between taxa, or even identifying individuals. Here, we present a DNA barcoding method as practical, hands-on approach that connects several experimental…

In this laboratory experiment, students evaluated three silver(I) complexes as potential additives for dental adhesives based on bacterial growth inhibition, heat stability, water insolubility, and cost-effectiveness. Each student prepared and analyzed a cyanoxime ligand and its corresponding silver(I) complex. Students characterized the…

Patch-clamp electrophysiological recordings of neuronal activity require a large amount of space and equipment. The technique is difficult to master and not conducive to demonstration to more than a few medical students. Therefore, neurophysiological education is mostly limited to classroom-based pedagogies such as lectures. However, the…

Chaotic phenomena are not part of standard curricula, although this subject offers several interesting aspects which can help students better understand basic features of science. A central observation is that even simple physical systems, if chaotic, are unpredictable, just like the weather. We present the principles applied when developing a…

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…

An easy operating tool has been developed for the quick measurement of thermoelectric power. The setup is made using a tweezer which consists of two circular copper plate electrodes. These copper electrodes are fixed to two arms of the tweezer which act as hot and cold probes. The setup has the very important advantage of easy sample mounting and…