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.
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.
Flash rocks, typically pieces of quartz that produce light when struck together, are an example of the complex phenomenon of triboluminescence. The green chemistry aspects for the flash rock demonstration are considered, and LEGO models illustrating quartz crystals, piezoelectric materials, and nonpiezoelectric materials are presented.
Why does the "Whoosh Bottle" experiment behave differently at different temperatures?
Educators may be able to use these anthocyanin experiments to make a connection between the food we eat and the chemical principles that are employed to ensure that canned foodstuffs can be preserved properly.
The major component of a non-carbonated drink such as KoolAid or a similar beverage is usually a fruit acid, either citric acid or malic acid. The titratable acid (H+) concentration of such drinks has been found to be in the range of 0.02 to 0.04 M. A weak acid-strong base titration of these drinks with 0.1 M NaOH solution is feasible as a student exercise. The use of such drinks as reagents is safe, convenient, and inexpensive. Experiment instructions are included.
This engaging activity uses wrapped and unwrapped candy to simulate alpha and beta decay.
The "Two-Faced" thionin reaction involves causing a purple solution to fade to colorless by shining light on the solution. I wondered if it could be demonstrated the color of light that caused this transition.
Flat, symmetrical molecules can be modeled by folding a sheet of paper, cutting patterns into the folded structure, and unfolding to produce the flat paper models. The finished models resemble paper snowflakes, but have a variety of rotational symmetries. Template patterns for several molecules are available for download in the Supporting Information.
For your enjoyment, we present lists of chemically-related words that end in the letters “-cation” but do not actually refer to the positively-charged chemical species. The lists are available for download in the Supporting Information.
