Questions we learned…but maybe forgot.
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Why is the sky blue?
Why are sunsets red?
Ahhh! I
need a
review!
A QUICK LOOK AT THE
ELECTROMAGNETIC
SPECTRUM
Objective for the day

By the end of the day…
 SWBAT
generalize and explain the relationship
between the color of light and wavelength within the
electromagnetic spectrum.
Remembering…
Electromagnetic Waves

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Electromagnetic waves are mostly invisible waves that carry
energy.
They have both electric and magnetic properties, hence the
name.
We already learned about radiation.

Radiation is energy that is transmitted by electromagnetic waves.
EM waves are all around you!
Classification of EM waves


Electromagnetic waves are classified according to
wavelength.
This is called the Electromagnetic Spectrum
longest wavelength
shortest wavelength
Know the order of the EM spectrum!
Ron’s Mother InVited Us to Xavier’s Garden
longest wavelength
shortest wavelength
Visible light
Know the order of visible light
longest wavelength
shortest wavelength
Know the order of the EM spectrum!
Ron’s Mother InVited Us to Xavier’s Garden
longest wavelength
shortest wavelength
Review & Practice

Q: Which has the LONGER wavelength:
Microwaves or Ultraviolet radiation?
longest wavelength
shortest wavelength
Review & Practice

Q: Which has the SHORTER wavelength:
Yellow light or X-rays?
longest wavelength
shortest wavelength
So why is the sky blue?
The sun shines down white light,
but white light is a mix of all of
the visible colors.


White light interacts with the atmosphere (nitrogen,
oxygen, and other gases).
So why is the sky blue?


Longer wavelengths
of light pass through
nitrogen and oxygen,
while shorter
wavelengths collide
and scatter.
We see the scattered
light, which is the blue
light.
Why are sunsets red?
Why are sunsets red?
Unit Overview
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Weather versus Climate
Clouds
Heat & Temperature
Density & Pressure
Water Cycle
Wind
Exit Ticket
1) Which has a SHORTER wavelength?
Red light or purple light
2) Order these according to INCREASING wavelength:
x-rays, ultraviolet, microwave, infrared
3) Give an explanation of why the sky appears blue.