Name: _________________________ Pd: ____
How are EM waves used in real life?
Type of Wave
1. Radio waves
2. Microwaves
3. Infrared
4. Visible light
5. Ultra Violet
6. X-rays
7. Gamma rays
How it’s used
The EM Spectrum
EM radiation can travel through empty space. This differentiates it from other types of waves, such as
sound, which need a medium to move through. All forms of EM radiation reside on the electromagnetic
spectrum, which ranks radiation from lowest energy/longest wavelength to highest energy/shortest
wavelength. The higher the energy, the stronger, and therefore more dangerous, the radiation. The only
difference between a radio wave and a gamma ray is the energy. Below is the electromagnetic spectrum at
a glance.
Radio: Radio waves have the longest wavelength in the electromagnetic spectrum (up to a football field
long). They are invisible to our eyes. They bring music to our radios, sound and picture to our televisions,
and carry signals to our cell phones. Cell phone waves are shorter than radio waves, but longer than
microwaves.
Microwaves: Also invisible, we use microwaves to heat our food quickly. Telecommunications satellites
use microwaves to transmit voice through the phone. Microwave energy can penetrate haze, clouds or
smoke, and thus is useful for transmitting information. Some microwaves are used for radar, like the
Doppler radar your weatherman uses on the news.
Infrared: Infrared lies between the visible and invisible portions of the EM spectrum. Your remote control
uses infrared light to change the channel. We feel infrared radiation every day via the sun's heat. Infrared
photography can detect temperature differences. Snakes can actually detect infrared radiation, which is
how they are able to locate warm-blooded prey in total darkness.
Visible: This is the only part of the electromagnetic spectrum we can see. We see the different
wavelengths in this band of the spectrum as the colors of the rainbow. The sun, for example, is a natural
source of visible waves. When looking at an object, our eyes see the color of light reflected, and all other
colors are absorbed.
Ultraviolet: Ultraviolet (UV) rays are what cause us to become sunburned. Humans can't see UV rays, but
some insects can. Our atmosphere's ozone layer blocks most UV rays. However, as our ozone layer depletes
due to use of chlorofluorocarbons (CFCs), UV levels are increasing. This can lead to health effects like skin
cancer.
X-rays: X-rays are very high-energy light waves. We're most familiar with their use in a doctor's office, but
X-rays also naturally occur in space. But don't worry, X-rays can't penetrate from outer space to the Earth's
surface.
Gamma rays: Gamma rays have the most energy and shortest wavelength of the entire spectrum.
Nuclear explosions and radioactive atoms generate these rays. Gamma rays can kill living cells, and medical
professionals sometimes use them to destroy cancerous cells. In deep space, gamma ray bursts occur daily,
but their origins are still a mystery.
Name: _________________________ Pd: ____
Electromagnetic Spectrum
1. In each of the following pairs, circle the form of radiation with the LONGER WAVELENGTH:
a.
b.
c.
d.
red light or blue light
microwaves or radio waves
infrared radiation or red light
gamma rays or UV radiation
2. In each of the following pairs, circle the form of radiation with the GREATER FREQUENCY:
a. yellow light or green light
b. x-rays or gamma rays
c. UV radiation or violet light
3. In each of the following pairs, circle the form of radiation with the LOWER ENERGY (energy is
directly related to frequency):
a. red light or blue light
b. microwaves or radio waves
c. infrared radiation or red light
d. gamma rays or UV radiation
e. yellow light or green light
f. x-rays or gamma rays
g. UV radiation or violet light
h. AM radio waves or FM radio waves
4. Name 3 types of EM waves that have a higher frequency than visible light waves.
a.
b.
c.
5. Name 3 types of EM waves that have a lower frequency than visible light waves.
a.
b.
c.
Directions: Use the word bank to answer the following questions. Each word will be
used only once.
Crest
Frequency
X-rays
Infrared
visible light
Trough
wavelength
Radio
Gamma
Ultra Violet
Wavelength
Longitudinal
Ultraviolet
X-Rays
Light
Amplitude
Electromagnetic
1.Visible
____________________
waves are used in doctor’s
offices and in airport security lines.
2. ____________________ is the distance between one point of a wave to the same point in the
next wave.
3. The ________________ is the top of a wave.
4. The ________________ is the bottom of a wave.
5. ___________________ waves are often used in heat lamps. .
6. ___________________ waves have the shortest wavelength and the highest frequency.
7. ___________________ waves have the longest wavelength and the lowest frequency.
8. ___________________ is the number of waves that pass by per second.
9. ___________________ is the only EM waves we can see with our eyes.
10. __________________ waves cause sunburn.