The noise level from exploding chemical demonstrations and the effect they could have on audiences, especially young children, needs attention. Auditory risk from H[subscript 2]- O2 balloon explosions have been studied, but no studies have been done on H[subscript 2]-air "eggsplosions." The peak sound pressure level (SPL) was measured…

The dramatic decrease in the cost of sequencing a human genome is leading to an era in which a wide range of students will benefit from having an understanding of human genetic variation. Since over 90% of sequence variation between humans is in the form of single nucleotide polymorphisms (SNPs), a laboratory exercise has been devised in order to…

Some new experiments using an improved version of the "tornado tube" are described here. The improved tornado tube consists of two plastic transparent bottles whose openings are connected with a ball valve, available at most hardware stores. After being filled with fluid and inverting, this tube allows demonstration of the generation,…

Due to a lack of time and, thus, an inability to present every possibility in a chemical reaction, organic chemistry professors tend to present each reaction with a single outcome. In practice, this is clearly not the case. A first-semester, three-week laboratory experiment designed for undergraduate organic chemistry students is described in…

In this article, we outline a demonstration that is relatively simple to perform but whose results require a quite subtle interpretation of Faraday's Law. When a very small magnet is dropped through a coil it can tumble as it falls leading to 'spikes' in the measured emf signal. The experiment, and demonstration, can be used in an introductory…

How to improve students' understanding of energy transformation and conservation remains one of the main challenges of energy teaching. To address this challenge, we developed a new teaching strategy suited to high school based on history and philosophy of science (HPS). It involves five key ingredients: study and reproduction of Joule's…

A pair of galvo mirrors reflecting light from a laser pointer is suggested for use as a school demonstration of Lissajous figures. The device is small, cheap and easy to assemble. Combined with a two-channel waveform generator, a full spectrum of excellently stable Lissajous figures can be generated (concerning frequency ratio, amplitude ratio and…

The introduction of the Wireless Smart Cart by PASCO scientific in April 2016 has ushered in a paradigm shift in the design and implementation of low-cost undergraduate physics and engineering laboratory experiments. The use of smartphones in experimental physics is by now widely accepted and documented. The smart cart in combination with…

Melanoma, a type of cancer that develops in melanocytes, is usually caused by direct exposure of skin to ultraviolet (UV) radiation resulting in cellular damage. In this study, a procedure to determine the effects of various commercial sunscreens with SPF values ranging from 15 to 100 was developed using pig skin to mimic human skin. These…

Earth's field nuclear magnetic resonance (EFNMR) spectroscopy offers students a unique opportunity to consolidate their understanding of NMR spectroscopic theory through hands-on practice with a simple spectrometer. A comprehensive, 6 h experiment is presented for the introduction of low-field NMR techniques, covering spectroscopy, relaxivity, and…

Herein we present a modified iodine clock experiment which replaces starch with cellulose paper. This provides the reaction with a white solid surface in which color change can be clearly observed and reduces reagent amounts required to 540 µL per group. After data acquisition, students are required to calculate reaction orders and the reaction…

Physics instructors recognize the value of kinesthetic experience in learning fundamental physics concepts. We describe a kinesthetic experiment appropriate for both college and high school physics students. The experiment helps students achieve an intuitive understanding of Newton's second law in a way they find quite enjoyable. It was devised by…

This work reports a rudimentary approach to teach and measure the kinetic friction coefficient using a smartphone that can effectively be employed for teaching purposes. More specifically, the kinetic friction coefficient, which is rather difficult to teach and measure, between various surfaces was determined by two different approaches using the…

This work describes the design, building, and testing of miniature, low-cost LED-LDR colorimeters for absorption-spectrophotometry experiments. It also describes using these colorimeters for simplified context-based-learning (CBL) activities in school teaching laboratories and for public-engagement events. The colorimeters are simple and robust,…

A simple, reliable, and cost-effective experiment is presented in which students synthesized citrate-capped gold nanoparticles (GNPs), functionalized them with poly(ethylene glycol) (PEG), and transferred the PEG-GNPs from water to the organic phase dichloromethane. The experiment introduces students to nanotechnology with foci on important…