Ionising Radiation
Radiation with enough energy to remove electrons from atoms, creating ions.
Unit
eV
In depth
Alpha and beta particles, gamma rays, X-rays and fast neutrons are all ionising. Ionisation within a cell can break DNA strands directly or generate reactive radicals from water, which is the mechanism of both radiation damage and radiotherapy.
Examples in the real world
Cosmic rays, radon decay products in buildings, medical X-rays and industrial gamma sources.