Materials:

• Paper
• cup
• 50 M&Ms or 50 skittles
• Napkin

Procedure:

1. With a partner, collect 50 pieces of “candium”
2. Place all “candiums” with the letters facing up. These are the unstable parent isotopes.
3. Fill in the appropriate numbers on the line on the table
4. Place candy in cup and roll candy for 10 seconds
5. Count the number of “M” side M&Ms and record under stable daughter isotope
6. Count the number of “blank” side M&Ms and record them under stable daughter isotope
7. Remove “blank” side candies and place them aside
8. Place “M” side M&M back in the cup, shake, and roll on napkin
9. Repeat until all of the “candiums” have decayed
10. Begin again for trail 2

Post-Activity Questions:

1. If a fossil contains 12.5% of carbon-14, how many half-lives has it undergone?
2. How many years have passed since the organism died?
3. The half-life of a certain radioactive element is 1,250 years. What would the ratio of parent-daughter be after 7,500 years?
4. The half-life of a certain radioactive element is 800 years, how old is an object if only 12.5% of the radioactive element remains?