Physical Chemistry

Investigating the Invisible: Attenuation of Radio Waves

In this Activity, students investigate properties of radiation using a handheld radio. Students compare the abilities of conductive and dielectric materials to attenuate or block, radio waves, and compare the attenuation of AM versus FM radio waves. The radio is placed inside different objects and students record which materials blocked or attenuated the waves.

Colors in Liquid Crystals

In this Activity, students investigate the relationship between temperature and composition and the reflected and transmitted colors of a common nanoscale material, the cholesteric liquid crystal.

Modeling Dynamic Equilibrium with Coins

This Activity explores factors that influence dynamic equilibrium, including how long it takes two populations to equilibrate, and the relative amounts of reactants and products present at equilibrium. Students first use concrete objects (coins), then progress to mathematical calculations of equilibrium without physically manipulating the objects.

Cool! Rates of Heating and Cooling

In this Activity, students measure the rate of warming for a chilled thermometer bulb held in room temperature air, for a chilled bulb held between two fingers, and for a few milliliters of ice-cold water. Students discover that the warming process is not linear. This Activity emphasizes the importance of measuring temperature change and its relevance to other experiments.

Turning on the Light

In this Activity, students investigate the luminescent properties of common items such as glow-in-the-dark stickers, wintergreen-flavored hard candies, and a chlorophyll solution made from spinach leaves. After making observations, they use a flowchart to categorize the luminescent items as fluorescent, phosphorescent, or triboluminescent.

Sink or Swim: The Cartesian Diver

In this Activity, students assemble a Cartesian diver and observe the effects of changing the pressure and temperature. An optional extension challenges students to cause the diver to hit the bottom in one minute by connecting the diver bottle to a second bottle in which baking soda and vinegar are reacted.

Rubber Bands, Free Energy, and Le Chatelier's Principle

In this Activity, students compare the temperature change of a rubber band that is quickly stretched compared to one that is quickly relaxed. They predict what effect the stress of heating will have on a stretched rubber strip and test their prediction.