The preparation of ethyl acetoacetate is a distinctive, century-old classic organic chemistry laboratory project. Ethyl acetate and sodium metal (sodium ethoxide) are reacted by Claisen ester condensation to produce the sodium salt of ethyl acetoacetate and then obtain the refined product by acidification as well as washing, drying, and…

If a ball rolls in a circular path on a horizontal surface at constant speed then its horizontal rotation axis changes direction with time. A simple experiment is presented showing that the torque applied to the ball is equal to the rate of change of its angular momentum, even though the magnitudes of its angular velocity and angular momentum…

Science and engineering practices (SEPs) and crosscutting concepts (CCs) constitute a significant part of "A Framework for K-12 Science Education" (NRC 2012). As teachers, the role of the authors is to highlight the pivotal role that both scientific knowledge and the practices used to generate knowledge play in learning. This article…

The family resemblance approach to nature of science is receiving increasing attention by science educators since its inception about a decade ago. Many scholars of science education have contributed and continue to contribute to it not only theoretically but also by applying it empirically to a wide range of areas such as curriculum and textbook…

We present a simple undergraduate level experiment dealing with the preparation and characterization of a colloidal Langmuir-Blodgett (LB) film. The experiment is designed to invoke an interdisciplinary understanding of colloid chemistry and surface science. It will allow the students to develop the concepts of wettability, hydrophobicity, and…

Measurements and calculations are presented showing how the trajectory of an object sliding across an inclined plane varies with the launch and incline angles. The trajectory depends on the magnitude and direction of the sliding friction force. The experiment is easy to set up, can be analysed using a video camera, and would be suitable for a…

Four General Chemistry instructors investigated the use of ChatGPT-4 to improve their lessons plans for the historical experiments of Thomson, Millikan, and Rutherford. The instructors varied in their prior knowledge for these experiments and their initial lessons addressed somewhat different learning objectives. This led to different…

Applying the idea of green chemistry, we extended an esterification teaching experiment with isoamyl alcohol and acetic acid and reused isoamyl acetate in the transesterification reaction with KOH as the catalyst. As a result, isoamyl alcohol was produced and could be reused for the teaching experiment. The simplified experimental method achieved…

The substitution of carbonyl compounds with liquid bromine as a brominating agent is the most commonly employed synthesis method for a-bromoacetophenone and its derivatives. However, liquid bromine possesses certain drawbacks, such as volatilization, high toxicity, strong corrosion, and poor reaction selectivity, which limit its application and…

Science is the study of the world around us, and a scientist's job is to ask questions about the world and then experiment to find the answers. There is not a more natural scientist than the Elementary child, whose reasoning mind is eager to ask questions, investigate, and discuss and compare findings with their peers. In this article, the authors…

The phyphox app has demonstrated itself to be useful and impressive for physics teaching. The app is free to download and has so many features that it seems it may be particularly helpful in this time of distance learning. Phyphox (pronounced to sound like "physics") works for Android and Apple phones, and there are many experiments…

In view of the mounting requirements for courses in nuclear chemistry and radiochemistry, hands-on experience in the separations of radioisotopes is imperative. Three separation techniques commonly used were introduced, coprecipitation, liquid-liquid extraction, and ion-exchange chromatography. Their principles and the associated fundamental…

The article describes a methodology for studying Fresnel diffraction with the active involvement of students in discussing the results of a demonstration experiment. To create a clearly visible model of Fresnel zones, a centimeter radio wave range was chosen, in which the first zone is about 10 cm in size. This makes visible the created…

The majority of chemical experiments conducted during educational programs are carried out in laboratories because they require instructors with special skills, in addition to large, expensive instruments. Recently, there has been an increasing demand for chemical experiments that can be carried out anywhere. Herein, we propose a novel type of…

Calculating analytical uncertainties as a part of method validation is a relevant aspect of field and laboratory practices in instrumental analytical chemistry subjects, which usually require complex algorithms. This work describes the development and didactic use of an automatic and straightforward informatics tool, implemented in an Excel macro,…