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.
Systems, Order & Organization
In this Activity, students compare the properties of nitinol metal wire (known as "memory" metal) and ordinary wire. Using the observed properties, they design (and possibly make) a toy that would use memory metal to operate. This Activity connects toys with science, and allows students to become inventors as they design a toy of their own.
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.
In this Activity, students collect soil samples and characterize them by examining their physical appearance, water holding capacity, sedimentation, and pH. Based on their observations, they can see that different samples of something as universal as soil can be quite different from each other. This environmental chemistry Activity can be used to complement a celebration of Earth Day.
In this Activity, students investigate microwave popcorn, the process of microwave-promoted popping, and the materials involved: water, vegetable oils, starch, and special packaging materials. This Activity supports discussion of thermal and electromagnetic energy, phase changes, intermolecular forces, patterns of solubility, and the structure of fats, oils and starches.
In this Activity, students use a commercial cement mix to produce concrete. They investigate how changing key variables such as concentrations, curing temperatures, and the addition of various substances affects properties such as setting time, hardness, and plasticity.
In this Activity, students test whether cans of carbonated beverages sink or float in water and then determine whether caffeine content, soda color, or sugar content in the carbonated sodas is responsible for the buoyancy of the sealed cans. This Activity can be used as an introduction to density in a middle school physical science course, or a high school chemistry or physics course.
In this Activity, students gain an understanding of the importance of reading reagent labels both in chemistry class and on consumer products. Students explore the chemistry behind the directive on a package of Kool-Aid "Do not store in a metal container". The Activity illustrates properties of acids and metals.
In this Activity, students marble paper with shaving cream and food color while exploring water, polarity, and hydrophilic and hydrophobic materials. Although the Activity is familiar, it contains a new twist—exploring how a colored shaving cream mixture behaves when a drop of water is added. This Activity can be used to introduce the concepts of polarity, soaps, and surfactants.
In this Activity, students examine the effect of pH on the intensity and color of the emission of fluorescent dyes in liquid laundry detergent. They perform two titrations using vinegar to estimate the pH at which the fluorescence properties change. In the second titration, sodium bicarbonate is added to buffer the detergent solution.