Teaching the noncommutativity of the product of matrices to high school or college level students is a difficult task when approached from a purely formal perspective. The aim of this paper is to present a simple experimental activity for teaching the noncommutativity of the matrix product, based on the Jones calculus, a mathematical formalism for…

We present an experiment designed to study standing waves in a tube with one closed end. Two smartphones are used, one to emit a sound signal with a chosen frequency and another equipped with a microphone to detect the sound pressure level inside the tube. Due to the finite diameter of the tube, the standing wave node (or antinode) appears…

[This paper is part of the Focused Collection on Instructional labs: Improving traditions and new directions.] In this paper, we describe the results of a research project whose goals were to (1) develop and implement video-based experimental investigations using the Investigative Science Learning Environment (ISLE) approach and (2) study how…

This report describes a laboratory experiment for an undergraduate-level inorganic chemistry or biochemistry course involving the study of the kinetics of the catecholase activity of a synthetic nickel­(II)-oximate complex. A model substrate, 3,5-di-tert-butylcatechol(DBC), undergoes aerobic oxidation to 3,5-di-tert-butylbenzoquinone (DBQ) in the…

Poinsettia ("Euphorbia pulcherrima") contains anthocyanins that dissolve in water and exhibit color changes due to changing pH. This property makes the poinsettia extract a useful acid-base indicator for pH demonstrations. When combined with common household materials, this experiment can be used as an alternative low-cost tool in…

MóviLab (Moving Lab) was an educational strategy developed at Universidad Industrial de Santander, Colombia, to promote chemistry and science among schoolchildren and teenagers from far rural areas of the Santurbán moor in Colombia during the COVID-19 pandemic. The strategy consisted of designing a kit with chemistry experiments that could be done…

Herein, two simulated electrochemistry experiments, namely, the (i) electrochemical series, using an electronic half-cell module, and (ii) citrus fruit battery series are demonstrated for undergraduate chemistry students. The demonstration can be performed for in-person and remote students by connecting the electronic half-cell module to a…

The essential component of expanding an undergraduate curriculum is the inclusion of lab experiments in nanoscience and nanomaterials, which significantly impact health and the environment through their use in food, cosmetics, agriculture, and medicine. We designed a laboratory experiment based on the atomic force microscopy (AFM) analysis of the…

Electrochemistry plays a crucial role in our everyday lives. It allows us to power our phones and cars and allows for the real-time monitoring of blood glucose levels. While electrochemistry is of vital importance and is a long-established field of chemistry, it is often neglected in modern curricula for STEM courses. Herein, we show that hands-on…

This study introduces a methodological framework for integrating STEM technologies into secondary school chemistry through project-based learning. The research aimed to boost students' interest and engagement in chemistry by involving them in a scientific project called "Water Purification Methods." Eighth-grade students from Kazakhstani…

A laboratory experiment was performed using tetra-n-butylammonium bromide (TBAB) ionic semiclathrate hydrate, a crystalline compound. Ionic semiclathrate hydrates have unique properties, and hence, novel technologies utilizing the ionic semiclathrate hydrates have been proposed to date. Thus, students could learn fundamentals of functional…

In a well-known bronze plating experiment, a Cu coupon is subjected to Sn plating and heating with a Bunsen burner. Currently, aqueous NaOH or HCl is typically used as the plating solution; however, the use of a strong acid or base provides operational risks, particularly in educational settings (e.g., schools). Herein, we introduce a modified…

Artificial intelligence (AI) is receiving a lot of attention in various fields. There is a need for educating students in AI technology. In this context, we have created a new type of carbon dioxide fountain by integrating AI with the well-established Arduino-carbon dioxide fountain experiment. This experiment consists of an Arduino…

This paper demonstrates the use of a smartphone's sensors in recording experimental data for investigating the large angle of a physical pendulum. The smartphone (iPhone 5s) was attached to a beam to record simultaneously both the angular position and the angular speed of the beam oscillating about the pivot. The period and phase space of the…

A handheld refractometer (HHR) is a versatile instrument in the chemistry lab or in the workplace. It is also inexpensive enough (<$25 U.S.) that all students in a chemistry lab can have one or students completing laboratories remotely can purchase one. We report four applications of two different HHRs: one HHR for which the scale reads…