A lot of the students said because they shook the containers differently... I also have students wash their hands before the activity, because of course after, the students eat the M&Ms. Radioactive decay and half-lives can be a very difficult concept for our 8th graders to grasp.They not only enjoyed this activity, but they really gained a better understanding of it as well.Students should have some prior knowledge of rocks and how they are dated. Materials Needed: -100 M&Ms (per group) -Notebook -Piece of Paper -Plastic Container with a Lid Lesson should be introduced by reviewing the 2 broad ways scientists age rocks (relative dating and radioactive dating).This activity would also be easy to adapt when talking about half-lives within a chemistry course. Also, review what a half-life is (info given the day prior during lecture/ notes/ reading).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.They will only re shake the radioactive M&Ms each time. Once they are finished with their 8 runs, they will record their data on the class data table (which can be on the board).To do this lesson and understand half-life and rates of radioactive decay, students should understand ratios and the multiplication of fractions, and be somewhat comfortable with probability.Games with manipulative or computer simulations should help them in getting the idea of how a constant proportional rate of decay is consistent with declining measures that only gradually approach zero.
They then gather the radioactive, or M side up M&Ms, put them back in the container, and then pour them out again. and continue this process until all M&Ms are stable, or M side down.
During each trial, students record the number of radioactive parent isotopes and record this in a data table.
Once all groups finish, each group records their info on the class decay table (on the board) and we calculate the averages of the class. Isotope Concepts: Students should begin to see the pattern that each time they dump out their M&Ms, about half become stable.
Adapted from: For Special Ed and ELL kids, you could give them a template of the data table/graph.
The first post question caused some confusion: Why didn't each group get the same results?