Neutrinos are perhaps the least understood of the known denizens of the subatomic world. They have nearly no mass, interact only via the weak nuclear force and gravity, and, perhaps most surprising, the three known species of neutrinos can transform from one variant into another. This transformation, called neutrino oscillation, has been…

Spin crossover (SCO) materials that switch between two different spin states, that is, the high spin (HS) and the low spin (LS) state, with very different optical, magnetic, and structural properties offer a unique platform to understand the consequences induced by the different electronic configurations of transition metal complexes. Due to the…

The application of physico-chemical principles has been routinely used to explain various physiological concepts. The Nernst equation is one example of this, used to predict the potential difference created by the transmembrane ion gradient resulting from uneven ion distribution within cellular compartments and the interstitial space. This…

The interference pattern between two harmonic oscillations with slightly different frequencies are called beats. The beats, as a combined motion, have two different periods, one approximately equal to the period of the original oscillations, and another that is significantly longer and is related to the variable amplitude of the motion. The main…

Why does a raindrop on a window pane show an image of the environment that is turned upside-down? And why does vision go blurry underwater, but is perfectly clear with diving goggles? Our everyday life is rich in optical phenomena. Unfortunately, these phenomena often play a subordinate role in Optics teaching, compared to ray constructions or…

A simple experiment is described to compare the descent time between two vertically separated points when an object slides down tracks of varying shape. A surprising result is that the descent time is shortest when it follows a circular track rather than a cycloidal track. Cycloidal tracks are usually predicted to result in the shortest descent…

Starting with a double replacement reaction in alcohol between Ni(H[subscript 2]O)[subscript 6](NO[subscript 3])[subscript 2] and NaX, students exploit solubility differences to produce a solution of NiX[subscript 2] and a NaNO[subscript 3] precipitate. They then synthesize a bis(N,N-diethylethylenediamine) Ni(II) complex with chloride, bromide,…

If a smooth ball is dropped vertically without spin on a smooth horizontal surface then one might expect the ball to bounce vertically without spin. If it does not then the centre of mass of the ball does not coincide with its geometric centre. An experiment is described where a billiard ball and a superball are deliberately biassed by adding a…

Chemical energy storage and use is a critical part of a sustainable world. In this laboratory experiment, students construct and use an inexpensive hydrogen fuel cell to power a calculator or a clock. The reusable cells are prepared from plastic syringes and a nickel mesh that is coated with a palladium metal catalyst by electroless deposition.…

The stately fall of magnets through conducting pipes is a favorite classroom and laboratory activity used in teaching electromagnetic induction, Lenz's law, eddy currents, electromagnetic braking, and even Newton's third law. When a neodymium magnet is used, the terminal velocity is reached in just a few milliseconds as the induced eddy currents…

To deliver state-of-the-art battery knowledge to undergraduates, we designed a feasible experiment to prepare flexible packaging batteries, aiming to reproduce industrial flexible packaging batteries in general chemistry laboratories. In our procedure, the materials involved are inexpensive, safe, and easy to use. No organic solvents or toxic…

A single latent fingerprint consists of ~50 µg of matter for which the anionic content often provides a differentiating characteristic between individuals. This forensic-themed, analytical chemistry experiment exploits this difference and has students employ ion-exchange chromatography to quantitatively analyze the anionic content of both…

The abstract definition of electric power as "ability of a voltage source to do work" or quantitatively as "energy per unit charge" is preceded by a qualitative description in terms of the existence of surface charges. These surface charges and the associated electric fields can be demonstrated experimentally and allow a causal…

An undergraduate laboratory experiment has been developed for the synthesis of a reactive cross-linker that is useful in various highly visual demonstrations of organic reactivity, click chemistry, and biobased polymer synthesis. A triazolinedione-based cross-linker, which is known as a useful reagent for click chemistry, can be obtained from…

Removing the pollutants from various wastewater is crucial to the environment, ecology, and humans. However, the pollutants are generally removed by chemical decomposition, which not only consumes a lot of energy but also produces carbon emissions. Electrochemical flocculation is effective to extract pollutant molecules and heavy ions from…