Half Life Modeling Activity
Learning Goal: Construct a decay curve for a hypothetical radioactive isotope which has a half life of 2 minutes. Practice with the concepts involved in radiometric dating.
- Cut out 100 .5x .5 inch squares out of printer paper. (you can use random.org coin flipper to model this if you don't want to use paper)
- On one side write H and the other write T on each piece.
- Drop the 100 pieces from eye level and allow them to fall to the floor.
- Count the number of heads and tails.
- H represents parent isotope atoms and T represents daughter atoms.
- Repeat the above procedure but only drop the parent isotopes. Remove the daughter atoms.
- Construct a decay curve for this isotope. On the Y axis plot number of parent atoms remaining. On the x axis plot the number of half lives.
- Each time you do a drop represents a half life.
- Complete each drop every two minutes.
- Repeat the procedure until you have no more parent isotopes remaining.
- How long did it take for all of your parent isotopes to decay?
- How many half lives took place?
- How old would a fossil be after the 4th half life according to your graph?
- What questions do you still have about radiometric dating?
- What was the ratio of parent to daughter atoms for each half life?
- Use your graph to find the age of the sample when 30 parent atoms remain.