Name ______________________________ Class _________________________
Electromagnetic Spectrum:
Click on the link above.
1. What is Electromagnetic Spectrum? The full range of frequencies, from radio
waves to gamma rays, that characterizes light.
2. What is radiation? Energy emitted in the form of waves (light) or particles
(photons
3. While in the website, roll the mouse over each of the following words and write
what comes up in the side box to describe each.
a. visible light Electromagnetic radiation at wavelengths which the human
eye can see. We perceive this radiation as colors ranging from red (longer
wavelengths; ~ 700 nanometers) to violet (shorter wavelengths; ~400
nanometers.)
b. microwaves, Electromagnetic radiation which has a longer wavelength
(between 1 mm and 30 cm) than visible light. Microwaves can be used to
study the Universe, communicate with satellites in Earth orbit, and cook
popcorn.
c. gamma-rays The highest energy, shortest wavelength electromagnetic
radiations. Usually, they are thought of as any photons having energies
greater than about 100 keV. (It's "gamma-ray" when used as an
adjective.)
d. Infrared Electromagnetic radiation at wavelengths longer than the red
end of visible light and shorter than microwaves (roughly between 1 and
100 microns). Almost none of the infrared portion of the electromagnetic
spectrum can reach the surface of the Earth, although some portions can
be observed by high-altitude aircraft (such as the Kuiper Observatory) or
telescopes on high mountaintops (such as the peak of Mauna Kea in
Hawaii).
e.
ultraviolet light, Electromagnetic radiation at wavelengths shorter than
the violet end of visible light; the atmosphere of the Earth effectively
blocks the transmission of most ultraviolet light.
f. X-rays and Electromagnetic radiation of very short wavelength and very
high-energy; X-rays have shorter wavelengths than ultraviolet light but
longer wavelengths than gamma rays.
g. radio waves Electromagnetic radiation which has the lowest frequency,
the longest wavelength, and is produced by charged particles moving back
and forth; the atmosphere of the Earth is transparent to radio waves with
wavelengths from a few millimeters to about twenty meters.
h.
4. What is the order of the spectrum from highest to lowest energy? Radio,
microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays
5. Which has more energy, A or B.? Describe
why. B has more energy because the waves
are closer together, therefore they have
more energy because they have a higher
frequency.
(a) Longer wavelength; (b) shorter wavelength.
6. Define a wavelength. The distance between adjacent peaks in a series of periodic
waves.
7. What is a frequency of a wavelength? A property of a wave that describes how
many wave patterns or cycles pass by in a period of time. Frequency is often
measured in Hertz (Hz), where a wave with a frequency of 1 Hz will pass by at 1
cycle per second.
8. For visible light, which has the shortest wavelength? RED Which has the
longest? VIOLET Place all the other colors in order based on their wavelength.
ROY G. BIV ( red, orange, yellow, green, blue indigo, violet)
9. Click on the link and answer the following questions:
a. What kind of electromagnetic radiation has the shortest wavelength?
Gamma The longest? Radio
b. What kind of electromagnetic radiation could be used to "see" molecules?
A cold virus? Ultrviolet
c. Why can't you use visible light to "see" molecules? Too small to see with
the naked eye. Must use higher frequency to cause molecules to
vibrate/move.
d. Some insects, like bees, can see light of shorter wavelengths than humans
can see. What kind of radiation do you think a bee sees? ULTRAVIOLET
10. Click on Behavior of light link.
a. What is reflection? Reflection involves two rays - an incoming or incident
ray and an outgoing or reflected ray.
b. Draw a picture of an angle of incident equaling an angle of reflection.
c. Explain the difference in how light will act on a smooth versus rough
surface. On a smooth surface, you will have a specular reflection. This
causes the light to bounce off exactly the same angle it came in. If it is a
rough surface, it is a diffused reflection and will scatter into different
directions.
d. Define Refraction. Refraction occurs when the light ray changes mediums.
Light traveling through air and then going through water is an example of
a light ray changing medium
e. Using proper terms, explain what is happening to the spoon in the water as
well as through a pot. The light entering in travels through a different
medium. Depending on the medium, the light will slow down. This will
cause the light ray to bend.
f. Click the page forward to see the different lenses as well as how the eye
perceives images. Explain the difference between concave and convex
lenses. Draw a picture of each and how the light hits it.
Concave mirror/lens bends inward like an hourglass. A convex is lens is thicker in the
middle then the sides. Concave bends the light rays in to the middle or center, while a
convex bends them outward on the sides and straight in the middle