Concept half life used radiometric dating
2) To familiarize students with the concept of half-life in radioactive decay.
3) To have students see that individual runs of statistical processes are less predictable than the average of many runs (or that runs with relatively small numbers involved are less dependable than runs with many numbers).
Return to top Each team of 3 to 5 students should discuss together how to determine the relative age of each of the rock units in the block diagram (Figure 1).
After students have decided how to establish the relative age of each rock unit, they should list them under the block, from most recent at the top of the list to oldest at the bottom.
On a piece of notebook paper, each piece should be placed with the printed M facing down. The candy should be poured into a container large enough for them to bounce around freely, it should be shaken thoroughly, then poured back onto the paper so that it is spread out instead of making a pile.
This first time of shaking represents one half life, and all those pieces of candy that have the printed M facing up represent a change to the daughter isotope.
But if there are too many neutrons, the nucleus is potentially unstable and decay may be triggered.That chance of decay is very small, but it is always present and it never changes.In other words, the nuclei do not "wear out" or get "tired".U-235 is the parent isotope of Pb-207, which is the daughter isotope.Many rocks contain small amounts of unstable isotopes and the daughter isotopes into which they decay.