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This unit investigates the origin of
colors in materials, including gasses, liquids, and solids. "Color in gasses" includes
experiments that explore the color of fireworks, the origin
of smog, the cause of rainbows, and why the sky is blue.
The "Color in liquids" section includes investigations
into why plants are green, the color change of acid/base
indicators, why objects change color when they rust, and
how glowsticks and fireflies produce colored light. The
section dealing with "Color in solids" examines how colors
are produced by the interference of light using an audio
CD, how UV light can be detected using fluorescence, and
how light emitting diodes work. Investigations are also
performed with materials that change color in response
to temperature (thermochromics), which are often used as
temperature indicators. The unit concludes with an investigation
into materials which change color in response to the application
of an electric current (electrochromics). |
