Half-lives for various radioisotopes can range from a few microseconds to billions of years.
See the table below for a list of radioisotopes and each of unique their half-lives. After 86 minutes, half of the atoms in the sample would have decayed into another element, Lanthanum-139.
The half-lives of certain types of radioisotopes are very useful to know.
They allow us to determine the ages of very old artifacts.
Scientists can use the half-life of Carbon-14 to determine the approximate age of organic objects less than 40,000 years old.
By determining how much of the carbon-14 has transmutated, scientist can calculate and estimate the age of a substance. Isotopes with longer half-lives such as Uranium-238 can be used to date even older objects.
In the field of nondestructive testing radiographers (people who produce radiographs to inspect objects) also use half-life information.A radiographer who works with radioisotopes needs to know the specific half-life to properly determine how much radiation the source in the camera is producing so that the film can be exposed properly.