Scientists use two kinds of dating techniques to work out the age of rocks and fossils. Older fossils cannot be dated by carbon methods and require radiometric.
Since the rock formation contains both types of fossils the ago of the rock formation must be in the overlapping date range of to million years.
Studying the layers of rock or strata can also be useful. If a layer of rock containing the fossil is higher up in the sequence that another layer, you know that layer must be younger in age.
Scientists can check their accuracy by using different isotopes.
The first radiometric dates, generated aboutshowed that the Earth was hundreds of millions, or billions, of years old.
That is, each team should stop according to their TIME paper at the end of the first timed interval 2 minutesor at the end of the second timed interval 4 minutesand so on.
After all the timed intervals have occurred, teams should exchange places with one another as instructed by the teacher.
The atoms in some chemical elements have different forms, called isotopes.
Then, count the number of pieces of candy left with the M facing down.
In a hypothetical example, a rock formation contains fossils of a type of brachiopod known to occur between and million years.
The same rock formation also contains a type of trilobite that was known to live to million years ago.
The task now for each team is to determine how many timed intervals that is, how many half-lives the set of pieces they are looking at has experienced. Both the team that turned over a set of pieces and the second team that examined the set should determine how many million years are represented by the proportion of U and Pb present, compare notes, and haggle about any differences that they got.