Radioactive dating worksheet
Students may confuse this random change of events with the non-random decay of radioactive isotopes.Stress the fact radioactive decay is not random and is highly predictable based upon past empirical data.Follow the directions from the Determining the Age of Fossils website for activity 2a.Before the lesson, the teacher should copy the data tables found in Figures 2 and 3 (on the website) and paste the tables to a student worksheet so that the students have a place to record their data.Example data set: Potassium-40 = 12 isotopes Argon-40 = 88 isotopes Half-life = 1.25 billion years Answer: Using the graph from the Exploration activity, this radioactive isotope has undergone three half-lives thus making the fossil (1.25 * 3 =) 5.25 billion years old.Grouping Suggestions: The teacher should assign small groups (2-3 students) to ensure diversity within the groups.
This lesson is geared to help take the "mystery" out of scientific dating of rocks and fossils.
During the discussion explain to students how this decay is at a set rate for a given element and that by measuring the percent rate of decay scientists can accurately predict the approximate age of a fossil or rock.
This is not to be confused with the statistical probability of the change in the population over time as demonstrated with an individual group's data during the M&Ms activity.
As the students work on the simulation they are visualizing how stability and change in natural or designed systems can be constructed by examining the changes over time (CCC Stability and Change), as well as analyzing and interpreting data (SP4).
This lesson is designed to help students understand the concepts of radioactive dating to help determine the approximate age of fossils and rocks.