Electromagnetic Waves
Spectrum Foldable
You need ONE sheet of Copy Paper
from the front
Cut along the dashed lines.
Fold on the solid line.
Gamma Rays
X-rays
Ultraviolet Rays
Visible Light
Infrared Rays
Microwaves
Radiowaves
outside flaps
Sketch a model of the Electromagnetic
This is also in the class reading
Electromagnetic Spectrum
• The full range of frequencies, from radio waves to
gamma rays, that characterizes light
• The electromagnetic spectrum can be expressed in
terms of energy, wavelength, or frequency. Each way
of thinking about the EM spectrum is related to the
others in a precise mathematical way.
Wavelength and Frequency
important vocabulary- copy on back of foldable
• For any kind of wave there
exists a simple relationship
between wavelength and
frequency.
• The wavelength (a) is
measured as the distance
between two successive
crests in a wave.
• The frequency is the number
of wave crests that pass a
given point in space each
second.
• (b has a higher frequency
that a)
Gamma Rays
• Shortest
wavelengths
• Highest frequencies
• Most penetrating of
all waves
X-rays
• Can penetrate most
matter
• Too much exposure can
cause cancer
• Useful in medicine
Ultraviolet Rays
• Energy is great enough
to damage or kill living
cells
• Insects can see this
Images of a Mimulus flower in visible
light (left) and ultraviolet light (right)
showing a dark nectar guide that is
visible to bees but not to humans
Visible Light
• We can see it!
• White light can be
separated into red,
orange, yellow, green,
blue, and violet
Infrared Rays
• Wavelengths are shorter
than radiowaves
• We feel them as heat
• Ex: heat lamps and
infrared cameras
Microwaves
• Radiowaves with the
shortest wavelengths
and highest frequencies
• Ex: radar guns
Radiowaves
• Longest wavelengths
• Lowest frequencies
• Used in broadcasting
•
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