Uranium-233 has a half-life of about 160000 years, on the other hand.
The half-life of carbon-10, for example, is only 19 seconds, so it is impossible to find this isotope in nature. Each radioactive element has a different half life decay time. Nevertheless, it is an approximation that gets very accurate when a sufficient number of nuclei are present. Half-life is defined as the time needed to undergo its decay process for half of the unstable nuclei. Half-life is a probabilistic measure - it doesn't mean that exactly half of the substance will have decayed after the time of the half-life has elapsed. This term can also be used more generally to describe any kind of exponential decay - for example, the biological half-life of metabolites. Uranium-233, on the other hand, has the half-life of about 160 000 years. For example, carbon-10 has a half-life of only 19 seconds, making it impossible for this isotope to be encountered in nature. Half of the people who learn they have melanoma of the foot die within five. Half-life is defined as the time required for half of the unstable nuclei to undergo their decay process.Įach substance has a different half-life. An extra 60 seconds could save your life.
Stable nuclei don't change, but unstable nuclei undergo radioactive decay, emitting alpha particles, beta particles or gamma rays and eventually decaying into a stable nuclei. Each radioactive material contains a stable and an unstable nuclei.