1. Copyright © 2011, InteractiveScienceLessons.com Radioactive Beans A lesson in the decay of radioactive nuclei

2. Copyright © 2011, InteractiveScienceLessons.com 1.Put 100 green peas in your cup 2.Sprinkle the peas onto your plate 3.Record observation 1 4.Remove peas that are FLAT SIDE UP. Count as you take those out 5.Replace each pea that comes out with a white lima bean 6.Record observation 2 7.Slide the peas & beans on plate back into cup 8.Repeat until all peas are gone: sprinkle, remove, replace, record Radioactive Beans

3. Copyright © 2011, InteractiveScienceLessons.com In the beginning…

4. Copyright © 2011, InteractiveScienceLessons.com 5 minutes later

5. Copyright © 2011, InteractiveScienceLessons.com Half have decayed after 10 minutes

6. Copyright © 2011, InteractiveScienceLessons.com

12. ObservationTime (minutes)Split peasLima beans 001000 128218 244951 363466 482080 5101189 612397

13. Copyright © 2011, InteractiveScienceLessons.com Radioactive Beans Number Of Radioactive Nuclei (# peas) Time, minutes 0 12 68 102 4 0 100 50 75 25

14. Copyright © 2011, InteractiveScienceLessons.com 2 Homework Questions- answer with 2 complete sentences on the back 1.What happens to radioactive elements over time? 2.What was the half life of your element in today ’ s activity? (at what exact point in time on your graph did you have 50 peas?)

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