science chapter 17 Flashcards
a wave that can travel through empty space and through matter
electromagnetic wave
energy carried by an electromagnetic wave
radiant energy
electromagnetic waves form when
a charge speeds up, slows down, or changes direction (charged particle vibrates)
electric fields surround
the charged particles
charged particles make
magnetic fields
magnetic fields make
changing electric fields
the connected magnetic and electric fields spread in all directions, creating
electromagnetic waves
Electromagnetic waves are what kind of waves
transverse
Electromagnetic waves travel through space at ________ km/s
300,000
electromagnetic waves travel slower in
matter
the sun emits energy by giving off
electromagnetic waves
On the sun, electromagnetic waves are produced with many different wavelengths because
The sun has different areas with different temperatures
Almost everything on earth emits
electromagnetic waves
The higher the electromagnetic waves energy,
the higher the frequency
Higher energy waves are
more dangerous for the skin
The changing motion of an electric charge produces
each type of electromagnetic wave
Every electromagnetic wave has a different _____, ______, and ________ _ ________ _____ __ _____.
frequency, wavelength, and carries a different amount of energy
the entire range of electromagnetic waves with different frequencies and wavelengths.
electromagnetic spectrum
The electromagnetic spectrum is organized based on…
wavelength and frequency
the lowest frequency, lowest energy electromagnetic wave that has a wavelength longer than 30cm. Used for communication for sound and sometimes video.
Radio wave
a low frequency, low energy, electromagnetic wave that is a little larger than a radio wave. Used for communication and satellite communications
microwave
an electromagnetic wave that has a wavelength shorter than a microwave but longer than light. You feel these wave while warming your hands near a campfire or when using a television remote.
Infrared waves
an electromagnetic wave that you can see in a rainbow of colors. Violet have the shortest wavelength and highest frequency.
light
an electromagnetic wave that has a slightly shorter wavelength and higher frequency than light and carries enough energy to cause chemical reactions. Can damage or kill skin cells, causing sunburn and skin cancer
ultraviolet waves
a high energy electromagnetic wave that has a slightly shorter wavelength and higher frequency than an ultraviolet wave. Used to scan your bones, but cannot hurt them due to calcium.
X-rays
a higher energy electromagnetic wave with a shorter wavelength and higher frequency than all other types of electromagnetic waves. So high energy that they can be used to destroy cancerous cells. Formed in space
Gamma Rays
the use of electromagnetic waves to send information in all directions
Broadcasting
Explain how radio/TV stations broadcast information
They send out radio waves at a certain frequency, and the station converts the sounds and images to electric signals. Then the signals are sent to your tv using an carrier wave, and they are converted back to images and sound.
an electromagnetic wave that a radio or television station uses to carry its sound or image signals
carrier wave
the station matches the _______ ____ and _______ ______.
carrier wave and electric signal
a change in the amplitude of a carrier wave
amplitude modulation (AM)
a change in the frequency of a carrier wave
frequency modulation (FM)
how a wave smoothly changes from high to low
analog
produces and sends out radio waves
transmitter
receives and changes the waves back into sound
antenna
waves that can carry more energy than radio waves, due to their shorter wavelength
microwaves
pass signals from your phone until it reaches the phone you call or text
cell towers
a worldwide navigation system that uses satellite signals to determine a receiver’s location
Global Positioning System (GPS)
vibrating molecules in any matter emit
infrared waves
the wavelength of infrared objects depends on the objects
temperature
The hotter the infrared object, the ___________ and ___________ produced.
greater frequency and shorter wavelength
Thermal cameras use what kind of wave to detect thermal energy loss?
infrared waves
Under certain lights, objects glow with this wave
ultraviolet
Medical ultraviolet waves are strong enough to
cure skin problems
the chemicals inside ultraviolet lights can power
lightbulbs
X Rays are used for
security and bone scans
Gamma rays are medically used for
destroying harmful tissue in paitents
