page_title: Ionizing radiation
section_title: Physical effects
hierarchical_section_title: Ionizing radiation / Physical effects
context_page_description: Ionizing radiation is radiation, traveling as a particle or electromagnetic wave, that carries sufficient energy to detach electrons from atoms or molecules, thereby ionizing an atom or a molecule. Ionizing radiation is made up of energetic subatomic particles, ions or atoms moving at high speeds, and electromagnetic waves on the high-energy end of the electromagnetic spectrum.
  Gamma rays, X-rays, and the higher ultraviolet part of the electromagnetic spectrum are ionizing, whereas the lower ultraviolet part of the electromagnetic spectrum and all the spectrum below UV, including visible light, nearly all types of laser light, infrared, microwaves, and radio waves are considered non-ionizing radiation. The boundary between ionizing and non-ionizing electromagnetic radiation that occurs in the ultraviolet is not sharply defined, since different molecules and atoms ionize at different energies. Conventional definition places the boundary at a photon energy between 10 eV and 33 eV in the ultraviolet.
  Typical ionizing subatomic particles found in radioactive decay include alpha particles, beta particles and neutrons.
caption: Ionized air glows blue around a beam of particulate ionizing radiation from a cyclotron
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