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.
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.