Radioactive dating lesson
Equipment that is necessary is M&Ms-- a lot because each group needs to begin with 100, and a container with a cover for each group.
Students should have the skill to set up a data table and a graph, however, if you want to use this activity with students that have not, you can provide them a template with that information.
Students should recognize each time the number should go down by appx half.
Then students take the class data and create a graph comparing the number of parent isotopes to the number of half-lives.
Once students are in their groups, with supplies, and general directions are given, they are on their own for doing their runs.
Students will record the number of M&Ms that are still "radioactive" (M side up) in their data table after each run, and set aside the "stable" (M side down) M&Ms.
Class size can vary, but activity should be done in groups of 2-3.
I ask the students to divide themselves into partners, and request that one partner to get a computer, while the second partner gets the record sheet they will use.
Although students could work through the simulation individually, I prefer partnerwork to foster discussion among students, encouraging scientific discourse (SP7).
Students measure the fluid depth with time for several "runs" with varied conditions, then graph their results, create decay equations, manipulate these equations and use them to "date" another experiment.
They then apply their new understanding to make predictions regarding complications involved in the decay process and its use in dating (such as daughter loss).