The Electromagnetic Spectrum - Download as PowerPoint by tyndale

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									The Electromagnetic Spectrum

          9th Grade
What is the electromagnetic
spectrum?
The entire range of electromagnetic wave
frequencies is called the electromagnetic
spectrum.
Radio Waves
Are low frequency electromagnetic waves
with wavelengths from less than a
centimeter to about 1000 meters.
Types of radio waves
Microwaves are radio wavelengths of about 1 to
10 cm.
Microwaves warm up food by making the
molecules in the food vibrate at incredible
speed. Sometimes the food is vibrated so fast
that the food molecules tear and
rip. Microwaves are absorbed by food, but the
microwaves do not make the food radioactive
because they turn into heat the minute they are
absorbed by food.
Radar
In radar, radio waves bounce off an object
to determine its speed and location.
MRI
In Magnetic Resonance Imaging (MRI),
radio waves produce an image of the inside
of the body.
Infrared Waves
Electromagnetic
waves with a slightly
higher frequency than
radio waves
People feel them as
thermal energy or
warmth
Visible Light
                Has wavelengths
                between 390 and 770
                billionth of a meter
                and can be seen with
                the eye
                ROYGBIV
                Red has the longest
                wavelength.
Ultraviolet Light
                    Have frequencies
                    slightly higher than
                    visible light and can
                    damage skin
                    Can kill bacteria
                    Can be absorbed by
                    some fluorescent
                    materials and released
                    as visible light.
The Ozone Layer
Absorbs most of the Sun’s harmful
ultraviolet waves.
X-rays and Gamma Rays
Are ultra-high-frequency electromagnetic
waves that can travel through matter, break
molecular bonds, and damage cells.
X-Rays are used to provide images of bones
and to examine suitcases at airports without
opening them.
Radiation therapy is used to kill diseased
cells.

								
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