The falling rod paradox, i.e. the fact that the tip of an almost horizontal rod falls with an acceleration 'higher than g', when the other end is hinged or supported, is a popular physics demonstration. It can be visualized by placing e.g. a coin on the tip of the rod and fixing a cup next to the coin. When the rod is released the free-falling…

Experimental results are presented concerning a bead sliding on a rotating, horizontal rod. If the rod rotates at constant angular velocity then the sliding speed in the radial direction increases exponentially with time, provided that the rotation speed is sufficient to overcome friction. Otherwise the bead rotates in a circular path of constant…

The contamination of wastewater with metals and the use of biotechnologies to remove them is commonly discussed in theoretical biology, microbiology and biotechnology classes aimed at undergraduate students. This work introduces an easy, economical and safe practical laboratory class related to this topic. The practice consists in performing batch…

The purpose of this laboratory experiment is to study fundamental concepts of kinetics and equilibria and the isotope effects associated with both of these concepts. The concepts of isotopes in introductory and general chemistry courses are typically used within the contexts of atomic weights and radioactivity. Kinetic and equilibrium isotope…

A highly visual, inexpensive, straightforward laboratory experiment for the determination of the activation energy of a demulsification process is presented. The experiment uses low-density polyethylene (LDPE) beads to clearly mark the interface between an NaCl(aq) solution and isopropanol. The NaCl(aq)-isopropanol system is shaken to produce an…

First-order kinetic decay rates can be obtained by measuring the time-dependent reflection spectra of ultraviolet-sensitive objects as they returned from their excited, colored state back to the ground, colorless state. In this paper, a procedure is described which provides an innovative and unique twist on standard, undergraduate, kinetics…

Lab-on-a-chip technology is brought into the classroom through development of a lesson series with hands-on practicals. Students can discover the principles of microfluidics with different practicals covering laminar flow, micromixing, and droplet generation, as well as trapping and counting beads. A quite affordable novel production technique…

In this study, we visualized the superposition principle of sound waves in a both-closed-end (BCE) resonance tube. The resonance tube is constructed using an acrylic tube with 2.64 cm internal diameter and 150 cm length, polystyrene beads to illustrate the positions of displacement nodes and antinodes and two identical detachable speakers as…

Today smartphones and tablets do not merely pervade our daily life, but also play a major role in STEM education in general, and in experimental investigations in particular. Enabling teachers and students to make use of these new techniques in physics lessons requires supplying capable and affordable applications. Our article presents the…

The catalytic hydrogenation of alkenes and alkynes is an important part of the undergraduate chemistry curriculum and is a fundamental process in chemical industry. Inquiry-based laboratory activities are presented that investigate the hydrogenation of alkynes on a nanoparticle palladium surface to form alkenes, which go on to form alkanes. Alkyne…

Surface structures on the nanometer size scale can impart new and exciting properties to bulk materials. Nanoscopic structures on hydrophobic materials can result in superhydrophobicity and structural coloration. We present an interdisciplinary experiment that introduces undergraduate students to nanotechnology by manipulating the…

Glass beads are placed in the compartments of a horizontal square grid. This grid is then vertically shaken. According to the reduced acceleration [image omitted] of the system, the granular material exhibits various behaviours. By counting the number of beads in each compartment after shaking, it is possible to define three regimes. At low…

Medical laboratory technology major was set up to meet rapid development of science and medical research technology in 2013. Students majoring in medical laboratory had learnt a lot of techniques distributed among different specialized courses. But, they did not understand why they had to learn these techniques and how they were applied in a…

This article describes a simple and inexpensive undergraduate-level kinetics experiment that uses magnetic levitation to monitor the progress and determine the activation energy of a condensation reaction on a polymeric solid support. The method employs a cuvette filled with a paramagnetic solution positioned between two strong magnets. The…

On a partly sunny afternoon, a fourth-grade class at the Marietta Center for Advanced Academics in Marietta, Georgia, was gearing up to explore key concepts regarding the nature of light. Armed with translucent beads and white pipe cleaners, the classroom teacher asked each student to count eight beads and then encouraged them to closely observe…