hand-out on the electromagnetic spectrum, prism, radiometer,
overhead projector
About this Activity:
This activity involves teacher demonstrations and class
discussions.
Procedure:
Pass out hand-out on the electromagnetic spectrum. Review
each
part of the spectrum with your students.
Use a radiometer to illustrate that infrared radiation is invisible
to the naked eye. Have students figure out how the radiometer
works, then discuss their responses.
Use the prism and the overhead projector to show the visible
spectrum. Turn off the lights in the classroom. Turn on the
overhead projector with the light projecting onto the ceiling or
upper wall. Hold the prism near the projecting surface so the
light can pass through the prism. The visible light spectrum
should appear on the wall or on a screen.
Discuss the visible spectrum with the students emphasizing that
each color has its own characteristic wavelength.