Name:______________________
Science 7
Date:________
Henke
NOTES: RADIATION & STARS (SEE ALSO ESRT PAGE 14)
Electromagnetic Radiation: Energy that travels through space in the form of waves.
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
Types of Electromagnetic Radiation:
1. Gamma Rays
2. X Rays
3. Ultraviolet light
4. Visible light
5. Infrared light
6. Microwaves
7. Radio waves
These types of radiation make up the ELECTROMAGNETIC SPECTRUM.
------- decreasing wavelength
--------increasing energy
-----------increasing frequency
increasing wavelength--------
decreasing energy ------------------
decreasing frequency -------------
All electromagnetic radiation travels in waves:
 Waves vary in wavelength and energy.
 Wavelength: distance between crests of adjacent waves.
Height of wave is called amplitude.
Number waves/time = Frequency
The symbol for wavelength is: “lambda”
*** As the wavelength (INCREASES, the energy level DECREASES.
Describe the slinky here: Low energy, long wavelength, few waves.
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*** As frequency INCREASES, the energy level INCREASES.
Describe the slinky here: high energy, short wavelength, many waves.
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SUMMARY:
Visible light:
RO Y G B I V
Long wavelength
Short wavelength
In the visible light spectrum, red has the longest wavelength and the lowest energy
level. Violet has the shortest wavelength and the highest energy level.
1.
Relate what you saw in the slinky demonstration to energy wavelength, frequency and
energy levels.
When a little bit of energy was put into the slinky, the wavelength was long, the
frequency was low. When high energy was put into the slinky, the wavelength was
short and the frequency was high.
2.
How do the wavelength and energy levels relate to the use of infrared (night
vision) goggles?
Night vision glasses convert invisible infrared wavelengths to the visible light
spectrum.
3. How do wavelength and energy levels relate to your skin and UV rays from the
sun?
Ultraviolet light has higher energy and shorter wavelength so it can cause more
damage than visible light.
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4. How does the electromagnetic spectrum help astronomers learn about stars?
The electromagnetic spectrum allows us to see the stars, as well as determine
the chemical composition of the stars by analyzing the light they emit.
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