Questions and Answers
What is an electromagnetic wave?
An electromagnetic wave is a wave that can travel through space (a vacuum) or through matter (a medium).
When traveling through a medium, EM waves are classified as longitudinal waves.
False
What is the relationship between frequency and wavelength?
High frequency waves have short wavelengths, and low frequency waves have long wavelengths.
How do electromagnetic waves differ?
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What is the relationship between wave frequency and energy?
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Identify the 7 main kinds of electromagnetic waves in order from lowest frequency to highest frequency.
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Identify the speed at which ALL electromagnetic waves travel through a vacuum.
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Describe the characteristics of gamma waves. Include how they are helpful & harmful.
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Describe the characteristics of x-rays. Include how they can be helpful & harmful.
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How are ultraviolet rays helpful?
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How are ultraviolet waves dangerous?
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What protection do we have against UV rays from the sun?
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Which EM wave has the lowest frequency and longest wavelength?
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Which part of the EM spectrum can be seen with our eyes?
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Identify the colors of visible light.
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Which color of visible light has the highest frequency? Which has the lowest frequency?
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Which color of visible light has the highest energy? Which has the lowest energy?
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What type of EM wave is given off by all objects?
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How are radio waves used?
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Which EM wave has a frequency just higher than radio waves? How are these waves used?
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A green object appears green because it absorbs all colors of light except __.
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Study Notes
Electromagnetic Waves
- Electromagnetic waves can travel through a vacuum or a medium.
- All electromagnetic waves are transverse, not longitudinal.
- Wavelength and frequency are inversely related: high frequency corresponds to short wavelength, while low frequency corresponds to long wavelength.
Characteristics of Electromagnetic Waves
- Variations in frequency, wavelength, and energy distinguish electromagnetic waves.
- High frequency waves possess short wavelengths and high energy; low frequency waves feature long wavelengths and low energy.
- Higher frequency waves indicate increased energy levels, resulting in greater potential danger.
Types of Electromagnetic Waves
- The electromagnetic spectrum consists of seven types of waves, ordered from lowest to highest frequency:
- Radio waves
- Microwaves
- Infrared waves
- Visible light
- Ultraviolet rays
- X-rays
- Gamma rays
Speed of Electromagnetic Waves
- All electromagnetic waves travel at a speed of 300 million meters per second in a vacuum.
Gamma Rays
- Gamma rays have the highest frequency and shortest wavelength, carrying maximum energy.
- They originate from radioactive elements and nuclear reactions.
- Helpful for killing cancer cells but harmful as they can damage or kill healthy cells.
X-Rays
- X-rays fall between gamma rays and ultraviolet waves in terms of frequency.
- They are beneficial for medical imaging but can harm healthy tissues.
Ultraviolet Rays
- UV rays can sterilize equipment and stimulate vitamin D production, aiding calcium absorption.
- Excessive exposure can lead to sunburn, skin aging, increased cancer risk, immune system weakening, and eye damage.
Protection Against UV Rays
- The ozone layer in the stratosphere helps block some UV light.
- Sunscreen effectively protects skin from harmful UV exposure.
Visible Light Spectrum
- Radio waves have the lowest frequency and longest wavelength within the spectrum.
- Visible light is a narrow section of the electromagnetic spectrum detectable by human eyes.
- Colors of visible light include red, orange, yellow, green, blue, indigo, and violet.
- Violet exhibits the highest frequency and energy, while red has the lowest.
Infrared Radiation
- All objects emit infrared radiation, recognized as heat.
Applications of Radio Waves and Microwaves
- Radio waves are essential for television and radio broadcasting.
- Microwaves are utilized for cooking and RADAR technology.
Color Perception
- An object appears green by absorbing all colors of light except green.
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Description
Test your knowledge of the electromagnetic spectrum with these informative flashcards. Learn definitions and key concepts about electromagnetic waves, their classifications, and the relationship between frequency and wavelength. Perfect for science students looking to reinforce their understanding of this essential topic.