Laboratory Exercise in Half-Life

Nuclear Physics M&Mium Experiment - Teacher Information

CTS Home - Student Worksheet

Half-life is sometimes a rather difficult concept to explain to students. At the end of this lab, students will understand the statistical nature of half-life as well as how it may be used to make predictions of the age as well as initial activity of a sample. What follows are directions that may be given to the students along with a large box with about 100 to 200 M&M candies in it.

Note: Some instructors may wish to avoid using semi-log paper, and therefore question 1 might be inappropriate. Some discussion questions that are helpful after this lab are the following.

1. Is it possible to tell when any single M&M will "decay"?

2. How could you predict the initial number of M&M's if all you knew was that on the fourth shake 120 M&M's decayed?

This lab will take about forty-five minutes to complete and may involve finishing the graphing work at home.