Ionizing radiation

Harmful high-frequency radiation

Ionizing radiation, also spelled ionising radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light; their electromagnetic waves are on the high-energy portion of the electromagnetic spectrum. Gamma rays, X-rays, and the higher energy ultraviolet part of the electromagnetic spectrum are ionizing radiation.

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