General EM
How many categories is the electromagnetic spectrum divided into?
7
What color is the longest wavelength of visible light that human eyes can see?
Red
How do astronomers get around the fact that the atmosphere blocks out so much of the EM spectrum?
They use space telescopes.
What advantage do space telescopes have over ground-based telescopes besides avoiding atmospheric interference?
They collect data 24 hours a day.
A ___________ can be used to split white light into different colors.
prism
Which type of electromagnetic wave has the highest energy?
Gamma rays
What blocks most electromagnetic radiation from reaching Earth's surface?
Earth's atmosphere
Which color of visible light has the most energy?
Violet
Which electromagnetic wave type would be most useful for seeing the temperature differences in objects?
Infrared radiation
These 3 types of radiation have energy greater than visible light.
Ultraviolet, X-rays, Gamma Rays
Which type of radiation has the second lowest energy?
Microwaves
Which electromagnetic waves are considered ionizing and can damage living tissue?
Ultraviolet, X-rays, Gamma Rays
These types of radiation mostly make it through the Earth's atmosphere without being blocked.
Visible light and radio waves
How did William Herschel discover infrared radiation in 1800?
He noticed his thermometer showed highest temperature beyond red light
These 3 types of radiation have energy less than visible light.
Radio Waves, Microwaves, Infrared
What unit is used to measure the frequency of electromagnetic waves?
Hertz
Why do different colors of light appear different to our eyes?
They have different wavelengths
Name the colors of the rainbow in order.
Red, orange, yellow, green, blue, indigo, violet
What is the main reason why longer wavelength electromagnetic waves have less energy than shorter wavelength waves?
They have lower frequency
"Ultraviolet" means:
Beyond violet
All electromagnetic waves travel at what speed?
300,000,000 m/s (the speed of light)
The frequency of the light humans can see is measured in
terahertz (THz)
When astronomers observe the galaxy Centaurus A using different types of radiation, what does this reveal?
Each type of radiation shows different information about the galaxy
Electromagnetic waves don't require a ________________ to travel through.
medium
The wavelength of light humans can see is measured in:
nanometers