demonstrations

Finding Flash Rocks

Flash rocks were discussed in a previous post as stones made of quartz that produce light by triboluminescence when struck together. This post provides some description of their origins and tips on how to find them, making connections to some of their properties.

Using My Marbles: Connecting Surface Area and Calorimetry with Temperature Curves and Thermochromic Cups

The importance of surface area can be illustrated by adding spherical solids at known sizes and temperature to other substances at different temperatures and then monitoring the rates of temperature changes of the system over time. Larger spheres (with less surface area per sample) exchanged heat with water more slowly than smaller spheres, and less thermally conductive glass spheres exchanged heat with water more slowly than iron spheres. Additional, more colorful demonstrations are described in which small glass spheres cool thermochromic plastic cups more quickly than larger glass spheres. 

Too Hot to Handle? Hydrogen Reacts with Oxygen on Palladium Foil

The reaction of hydrogen and oxygen gases to form water is well known to be an exothermic reaction. That reaction can occur by first absorbing the hydrogen into palladium metal, and then placing the resulting palladium hydride into contact with oxygen in the air. Infrared and visible light videos were recorded for this process involving palladium foil, and the Green Chemistry and safety aspects of these activities are considered.