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.
Let's look closely at how the half-life affects an isotope. Therefore, after one half-life, you would have 5 grams of Barium-139, and 5 grams of Lanthanum-139.
Scientists use this natural How do scientists find the age of planets (date samples) or planetary time.
there are other things that scientist use to try to understand Earth. geologic time scale, including formation of the Earth,.
They allow us to determine the ages of very old artifacts.