In this Activity, students extract a fluorescent substance from shavings of narra wood. The pH-dependent fluorescence can be turned on and off using household acid and base solutions. A yellow filter blocks the exciting light but not the fluorescent emission. This Activity gets students thinking about the interaction of light and molecules.
In this Activity, students use their deductive reasoning skills as they identify formulas of unknown elements and compounds modeled by paperclips. Each color of paperclip represents a different element, with linkages between different paperclips in appropriate ratios representing 20 unknowns.
In this Activity, column chromatography separations are simulated using a grid, colored paper squares, and a six-sided die. Students observe the effects of changing flow rate, column length, and mobile phase composition. As squares come off the grid, the separation (or lack thereof) of the colors is noticeable.
In this Activity, students simulate Millikan’s oil drop experiment using drop-shaped magnets and steel BBs. Students determine the mass of a single BB analogous to the way Millikan determined the charge of a single electron.
In this Activity, students explore buoyancy with helium-filled Mylar balloons. They use the ideal gas law to predict the mass of the balloon if it were empty, compare it to the actual mass of the empty balloon, and discuss experimental sources of error. This Activity demonstrates the ideal gas law and introduces students to the concept of buoyancy.
In this Activity, students make funnels using plastic beverage bottles and rubber stoppers with differing numbers of holes or sizes of holes. They then determine the rate of flow of water through the funnels and identify factors that affect the rate of flow. This Activity uses easy-to-observe phenomena that model a chemical reaction with an identifiable rate-controlling step.
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 use a colorimetric visualization test to screen grape juice for phenolic content. Students use the test to examine differences in phenolic content of juices prepared with different processing methods. Most of the materials are readily available at the supermarket.
In this Activity, students predict whether a given bowling ball will float or sink in tap water. Students design a procedure to collect radius and weight measurements to calculate the density of their ball. They then test their prediction by placing the ball in a large container of water, which yields the surprising observation that some bowling balls do float.
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.