Electromagnetic Spectrum
Which EM wave has a frequency just higher than radio waves? How are these waves used?
Microwaves are high frequency radio waves. Microwaves are used to cook food and are used in RADAR technology.
Which EM wave has the lowest frequency and longest wavelength?
Radio waves
How are radio waves used?
Radio waves are used in television and radio broadcasting
Identify the 7 main kinds of electromagnetic waves in order from lowest frequency to highest frequency.
The 7 main electromagnetic waves in order from lowest frequency to highest frequency: 1. radio waves 2. microwaves 3. infrared waves 4. light 5. ultraviolet waves (rays) 6. x-rays 7. gamma rays
Identify the colors of visible light.
The colors of visible light are: Red, orange, yellow, green, blue, indigo, violet
Electromagnetic waves differ in frequency (and wavelength). What is the relationship between wave frequency and energy?
The higher the frequency, the higher the energy- the more dangerous the EM wave is. The lower the frequency, the lower the energy - the less dangerous the EM wave is.
How are ultraviolet waves dangerous?
UV rays cause sunburn, premature aging (wrinkles), increase the risk of skin cancer, weaken the immune system and harm our eyes.
How are ultraviolet rays helpful?
Ultraviolet waves can be used to sterilize equipment (kill bacteria and other disease-causing organisms). UV rays also stimulate skin cells to produce Vit D, which is needed for the absorption of calcium by the body
Which color of visible light has the highest energy? Which has the lowest energy?
Violet has the highest energy. Red has the lowest energy.
Which part of the EM spectrum can be seen with our eyes?
Visible light is a narrow portion of the spectrum that is visible to our eyes.
Describe the characteristics of x-rays. Include how they can be helpful & harmful.
X-rays have a lower frequency than gamma rays but a higher frequency than ultraviolet waves. Helpful: used to see inside the bodies of living things or objects (ex: airport luggage) Harmful: damages healthy cells of an organism (a living thing)
A green object is appears green because it absorbs all colors of light except ____.
green
What protection do we have against UV rays from the sun?
1. The ozone shield in the stratosphere blocks/prevents some UV light from reaching Earth's surface. 2. Applying sunscreen is also an effective way to block UV light from damaging the cells of your body.
Identify the speed at which ALL electromagnetic waves travel through a vacuum.
All EM waves travel 300 million meters/second in a vacuum.
What type of EM wave is given off by all objects?
All objects give off varying amounts of infrared radiation (which is detected as heat)
What is an electromagnetic wave?
An electromagnetic wave is a wave that can travel through space (a vacuum) or through matter (a medium)
How do electromagnetic waves differ?
EM waves differ in frequency, wavelength and energy level. + High frequency waves have short wavelength and HIGH energy. + Low frequency waves have long wavelengths and low energy.
True or False: When traveling through a medium, EM waves are classified as longitudinal waves.
False: All EM waves are transverse waves.
Describe the characteristics of gamma waves. Include how they are helpful & harmful.
Gamma waves have the highest frequency, shortest wavelength and therefore, carry the greatest amount of energy. -Source: certain radioactive elements & nuclear reactions -Helpful: used to kill cancer cells - Harmful: can alter or kill healthy body cells
What is the relationship between frequency and wavelength?
High frequency waves have short wavelength. Low frequency waves have long wavelengths.
Which color of visible light has the highest frequency? Which has the lowest frequency?
Highest frequency - violet Lowest frequency -red
