This blog post includes short descriptions of demonstrations and props that Dean Campbell has used while teaching his collegiate General Chemistry I course.
The classic classroom or lab activity using coin flips to illustrate the first order kinetics of radioactive decay is connected to the tragedy of radiation exposure of workers at facilities using radium-containing luminescent paint. Some of the chemistry related to the contamination of these “radium girls” is explored, with connections being made to the Principles of Green Chemistry and the United Nations Sustainable Development Goals.
Thin sheets of polystyrene can be patterned with permanent markers to represent repeating units of the polymer and then shrunk down in size using heat. The shrunken models of the repeating units can be connected with a string and then flipped into positions to demonstrate different types of polymer tacticity.
Atomic theory is a common topic throughout any introductory chemistry course. It is likely that Rutherford’s gold foil experiment gets at least some attention in your course. This simple activity gives students an opportunity to replicate Rutherford’s experiment through an analogy experiment that may allow for easier conceptualization of the experiment itself and provide additional support for model development.
Addition of a small amount of azobenzene to eicosane can lower its melting point to where it can be melted by body heat. This can be used in demonstrations and classroom activities related to freezing point depression and phase diagrams.
Thermal paper such as that used for point of sale receipts typically functions by darkening when exposed to heat. The pigment system used in this paper also darkens when exposed to solvents of intermediate polarity and acids. This enables thermal paper to be used as an inexpensive sort of indicator paper for a variety of demonstrations.
The differing electrostatic and solubility properties of starch and polystyrene foam packing peanuts are used in various demonstrations to describe aspects of microplastics and their interactions with the environment. Their differing responses to exposure to liquid nitrogen and iodine solutions are also described.
The many colors of springtime can be illustrated with photochromic pigments in commercial products. These products include UV beads, and more recently, photochromic glue. The glue can be used as a photochromic paint for paper or even eggs. The resulting colorful, decorative objects can be used to illustrate chemical discussions of aspects of photochemistry.
The blossoms of eastern skunk cabbage produce heat for a couple of weeks in early spring. This heat, which can be detected using an infrared camera, results from oxidation of carbohydrates. The mechanisms behind this process can be used to introduce energy transduction during classroom discussions of thermochemistry.
The authors revisit "flattening the curve" demonstrations published during 2020 to see how they could represent the impact of vaccinations on the COVID 19 battlefront. These demonstrations do not demonstrate the mechanisms of vaccines themselves, but are rather analogies to their potential effect on a population. In these analogies, gas production still represents illness, but this time people are represented by objects added to the solutions which either enable gas production (unvaccinated individuals) or do not enable gas production (vaccinated individuals). These simple experiments are best used as stand-alone demonstrations, and links to videos are included in this writeup.
