Quantum dots (QDs) are useful for demonstrating the particle-in-a-box (PIB) model utilized in quantum chemistry, and can readily be applied to a discussion of both thermodynamics and kinetics in an undergraduate laboratory setting. Modifications of existing synthetic procedures were used to create QDs of different sizes and compositions (CdS…

The purpose of this paper is to present and discuss an alternative solution to an experimental problem given to high school students in the XXII Ibero-American Physics Olympiad held by Colombia this year. From the measurements of electric current and potential difference across a small tungsten filament lamp students should find the dimensions of…

This experiment prepares a large (M[subscript r]: 1821 g mol[superscript -1]) triple helicate complex quickly in one pot from inexpensive starting materials. The protocol illustrates the power of self-assembly in a simple manner that is suitable for second-year general chemistry students using reversible imine bond and metal-ligand bond formation.…

An introductory general chemistry laboratory course was developed to provide an authentic research experience in environmental chemistry. First- and second-year students learned general chemistry concepts and laboratory skills in the context of snow chemistry while participating in the course-based undergraduate research experience. Students were…

In this laboratory experiment, students performed thermogravimetric analysis (TGA) coupled with mass spectrometry (MS) of herbaceous materials (TGA-MS) and learned to analyze mass-loss curves, as well as identify common fragmentation ions. The experiment is the first one to present the application of TGA in a currently relevant topic: biomass…

Laboratory reports written in the style of a standard scientific article are commonly used to assess student learning in biochemistry laboratory courses. While most students can complete the Materials and Methods or Results sections successfully, many have difficulty with the Introduction and Discussion. They fail to place their data in a larger…

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…

FlashPhotol is an educational software package that introduces students to the kinetics of transient species and fast reactions. This is achieved by means of a computer-simulated flash photolysis apparatus that comprises all major functional elements and that students can use to perform various experiments. The experimental interface presents a…

It has been the author's experience over many years, no doubt shared by others, that a stick of chalk usually breaks into three pieces when accidentally dropped onto the floor. I rarely gave it any thought, apart from noting that the fundamental mode of vibration of a freely supported, rigid rod has two nodes at an equal distance from each…

Students are well aware of the effect of the deflection of sports balls when they have been given a spin. A volleyball, tennis, or table tennis ball served with topspin results in an additional downward force that makes the ball difficult to catch and return. In soccer, the effect of sidespin causes the ball to curve unexpectedly sideways,…