Radio waves are a type of electromagnetic radiation characterized by having the longest wavelengths and the lowest frequencies in the electromagnetic spectrum. Their wavelengths can range from about 1 millimeter to over 100 kilometers, and their frequencies typically fall below 300 gigahertz (GHz)
. They are generated by accelerating charged particles, such as electrons moving back and forth in an antenna, which creates oscillating electric currents that radiate radio waves. Naturally, radio waves are also emitted by phenomena like lightning and astronomical objects such as the Sun and galaxies
. In a vacuum, radio waves travel at the speed of light, approximately 299,792,458 meters per second, and slightly slower in the Earth's atmosphere
. Radio waves are widely used in modern technology for communication purposes, including radio and television broadcasting, cellular phones, radar, satellite communications, and wireless networks. They carry information by modulating their amplitude or frequency, allowing data, audio, and images to be transmitted over long distances
. In summary, radio waves are electromagnetic waves with very long wavelengths and low frequencies, essential for wireless communication and naturally occurring in various cosmic and atmospheric processes
