2007-10-02 20:47:39 · 3 answers · asked by ally 2 in Science & Mathematics ➔ Earth Sciences & Geology
by the rate of the half-life
http://www.sciencecourseware.org/VirtualDating/files/2.0_HalfLife.html check out this site, it will teach you how to measure age of rocks and minerals.
2007-10-02 20:53:32 · answer #1 · answered by Kristenite’s Back! 7 · 2⤊ 0⤋
The property that allows them to be used to determine the age of rocks and fossils is that they decay at a known and constant rate. Every radioisotope has a half-life; that is, a period of time during which half of its nuclei will decay into more stable nuclei. If you know a radioisotope's half-life, and if you know how much of it was originally present in a sample, you can tell how long the sample has been decaying based on the fraction that remains. Now if you want to learn about how scientists determine how much of a radioisotope was originally in a sample, that's a whole other question.
2016-05-19 21:22:02 · answer #2 · answered by ? 3 · 0⤊ 0⤋
Because the level of radioactivity decays or decreases at a set rate.
2007-10-02 21:41:17 · answer #3 · answered by Curious Cat 3 · 0⤊ 2⤋