Definition:
The electromagnetic spectrum is the range of all types of electromagnetic radiation, arranged according to their wavelengths or frequencies. This spectrum includes a wide variety of waves, from very long radio waves to very short gamma rays.
Key Regions of the Spectrum:
-
Radio waves: Longest wavelengths, used in communication like TV, radio, and cell phones.
-
Microwaves: Used in cooking (microwave ovens) and radar technology.
-
Infrared (IR): Felt as heat, used in remote controls and thermal imaging.
-
Visible light: The small portion of the spectrum that human eyes can see, from violet to red.
-
Ultraviolet (UV): Beyond visible light, can cause sunburn; used in sterilization.
-
X-rays: High-energy waves used in medical imaging.
-
Gamma rays: Shortest wavelengths, highest energy, emitted by radioactive materials and cosmic sources.
Important Concepts:
-
All electromagnetic waves travel at the speed of light (~300,000 km/s in vacuum).
-
Wavelength and frequency are inversely related: longer wavelengths have lower frequencies and vice versa.
-
Electromagnetic radiation carries energy and can interact with matter in various ways.
-
Different parts of the spectrum have different applications in science, medicine, technology, and communication.