Journal of Geology & Geophysics
Open Access

Particle Radiation

Through this process — called radioactive decay — radioisotopes lose their radioactivity over time. This gradual loss of radioactivity is measured in half-lives. Essentially, a half life of a radioactive material is the time it takes one-half of the atoms of a radioisotope to decay by emitting radiation. This time can range from fractions of a second (for radon-220) to millions of years (for thorium-232). When radioisotopes are used in medicine or industry, it is vital to know how rapidly they lose their radioactivity, in order to know the precise amount of radioisotope that is available for the medical procedure or industrial use