These sites explain how radio waves are a part of the electromagnetic spectrum. Includes information about AM and FM frequencies and how to measure waves. Also includes a biography on Marconi, inventor of the radio. Includes several animated movies, hands-on activities and interactive quizzes. There is a link to an eThemes Resource on sound.
This site provides a good overview of waves and electromagnetic waves. Follow the links to view short and long waves, including radio waves. Also mentions microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays.
This interactive page lets you adjust the energy of waves, then measure its frequency and wavelength. Explore the entire site for more on waves, and be sure to click on "Brain Teasers" and "Light Facts" on every page.
A brief biography of Guglielmo Marconi, the inventor of the radio. Click on "Radio Transmission" at the bottom of the page for an interactive activity with audio. Change the wave frequency and listen to the result. Requires Shockwave.
Read an explanation on how radios work. Click on "Next Page" at the bottom to start. Both amplitude modulation and frequency modulation waves are discussed. NOTE: The site includes pop-up and banner ads.
Watch a movie that explains how radio works and how radio signals are transmitted. There are topics on electromagnetic spectrum, radar, and cellphone. Includes activities and a quiz at the bottom of a page. NOTE: This site requires a subscription.
These sites explain sound waves and how the ear hears sounds. Includes information on sonic booms and decibels. Listen to a variety of sounds, play a virtual piano, watch movies about sound, or try several hands-on experiments.