Atomic and Molecular Structure

How a Photon Is Created or Absorbed

Giles Henderson
Eastern Illinois University, Charleston, IL 61920

Robert C. Rittenhouse
Walla Walla College, College Place, WA 99324

John C. Wright and Jon L. Holmes
University of Wisconsin-Madison, Madison, WI 53706

A Refrigerator Magnet Analog of Scanning-Probe Microscopy

In this Activity, students investigate the magnetic interactions between a flexible-sheet refrigerator magnet and a probe tip cut from the same magnet to deduce the relative arrangement of the magnetic poles. These interactions are used as a macroscopic analog of scanning probe microscopies. The Activity could be used when atoms are introduced.

Burning to Learn: An Introduction to Flame Retardants

In this Activity, students test common household substances to see how they change the way paper burns. Strips of filter paper are soaked in saturated solutions, dried, and briefly held in a flame. The Activity demonstrates the effectiveness of flame retardants. It could be used when discussing combustion reactions or during a unit on practical or everyday chemistry.

Charge It! An Activity with Electricity

In this Activity, students investigate static electricity. They observe that charged objects attract a narrow stream of water, and find that charged combs and glass rods have opposite charges. This Activity could be used to introduce the notion of positive and negative electric charge. It is appropriate when studying atomic theory, and when introducing electrochemistry.

How Many Colors in Your Computer? Discovering the Rules for Making Colors

In this Activity, students investigate the colors displayed on a computer monitor with a magnifying glass. They then mix colors first using light, then using paints or crayons. This Activity could be used in discussions of solid state chemistry when LEDs, phosphors, or liquid crystals are discussed.

CD Light: An Introduction to Spectroscopy

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.

Putting UV-Sensitive Beads to the Test

In this Activity, students observe UV-sensitive beads that have been melted into flat disks, explore the temperature behavior of the disks, and then use the disks to investigate the effectiveness of different sunscreens. The Activity shows applications of chemistry in the real world.

LEDs Are Diodes

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.