Students not only want to know how old a fossil is, but they want to know how that age was determined.Some very straightforward principles are used to determine the age of fossils.
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.
If the nucleus has not yet decayed, there is always that same, slight chance that it will change in the near future.