5.44. Electromagnetic Spectrum http://www.ck12.org
5.44 Electromagnetic Spectrum
- Describe electromagnetic radiation and its properties.
- Give an overview of the electromagnetic spectrum.
It’s a warm sunny Saturday, and Michael and Lavar have a big day planned. They’re going to ride across town to
meet their friends and then go to the zoo. The boys may not realize it, but they will be bombarded by electromagnetic
radiation as they ride their bikes and walk around the zoo grounds. The only kinds of radiation they can detect are
visible light, which allows them to see, and infrared light, which they feel as warmth on their skin.
Q:Besides visible light and infrared light, what other kinds of electromagnetic radiation will the boys be exposed to
in sunlight?
A:Sunlight consists of all the different kinds of electromagnetic radiation, from harmless radio waves to deadly
gamma rays. Fortunately, Earth’s atmosphere prevents most of the harmful radiation from reaching Earth’s surface.
You can read about the different kinds of electromagnetic radiation in this article.
Electromagnetic Radiation
Electromagnetic radiation is energy that travels in waves across space as well as through matter. Most of the
electromagnetic radiation on Earth comes from the sun. Like other waves, electromagnetic waves are characterized
by certain wavelengths and wave frequencies. Wavelength is the distance between two corresponding points on
adjacent waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time.
Electromagnetic waves with shorter wavelengths have higher frequencies and more energy.