In this Activity, students compare incandescent bulbs and LEDs powered by dc and ac voltage sources. They use circuits made from cut-up holiday light strands, with some of the incandescent bulbs replaced with LEDs. The diode nature of LEDs is demonstrated, as well as the energy associated with different wavelengths of light.
This Activity illustrates sublimation/deposition with dichlorobenzene (mothballs) and evaporation/condensation with water. This Activity could be used to introduce the phases of matter and phase changes at both the macroscopic and microscopic levels.
In this Activity, students use a CD to build a simple spectroscope. They use it to investigate how different colors of light interact with colored matter. This qualitative Activity could be used as a general introduction to spectroscopy and the concepts of complementary colors and absorbance.
In this Activity, students make a chemical clock using chemicals found in the supermarket: vitamin C tablets, tincture of iodine (2%), hydrogen peroxide (3%), and liquid laundry starch. They investigate what happens to the speed of the clock when the reactant solutions are made more or less dilute.
In this Activity, students investigate the chemistry of the popular Salt Crystal Garden. They grow salt crystals by evaporation from aqueous solutions containing various mixtures of table salt, ammonia, and laundry bluing in order to determine the purpose of each component.
In this Activity, students extract DNA from liver and onion cells, and precipitate the DNA. The Activity fits well with a discussion of nucleic acids, hydrogen bonding, genetic coding, and heredity. DNA extraction can also be used in conjunction with a discussion of polymers and their properties.
In this Activity, students use building-block car kits to explore stoichiometry in a concrete manner. They determine the relationship between the number and mass of each required car component (the pieces in the kit) and the mass of the final product (the completed car). This Activity works well as either an introduction or review of stoichiometry.