Radiation and wavelength are related concepts but refer to different aspects of electromagnetic waves.
Radiation: Radiation refers to the emission or transmission of energy in the form of electromagnetic waves or particles. It encompasses a wide range of phenomena, including the release of energy from a source, the transmission of that energy through space, and the detection or absorption of the energy by objects or organisms. Radiation can occur in various forms, such as radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Each of these forms has different properties and interactions with matter.
Wavelength: Wavelength, on the other hand, is a specific characteristic of electromagnetic waves. It refers to the distance between two consecutive points in a wave that are in the same phase. In simpler terms, it is the distance from one peak or crest of a wave to the next peak or crest, or from one trough to the next trough. Wavelength is usually denoted by the Greek letter lambda (λ) and is measured in units such as meters (m), centimeters (cm), or nanometers (nm).
Wavelength is an essential property of electromagnetic waves and determines their characteristics, including the type of radiation and its behavior. Different types of radiation have distinct wavelength ranges. For example, radio waves have relatively long wavelengths (ranging from meters to kilometers), while gamma rays have very short wavelengths (measured in picometers or smaller).
In summary, radiation refers to the overall phenomenon of energy transmission in the form of electromagnetic waves or particles, while wavelength specifically denotes the distance between consecutive points in a wave of electromagnetic radiation.