Half Life Of Candy Instructions W16 PDF

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Dr. F...

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End of Semester BONUS! Radioactive Half-Life: The Half life of…Candy “The Half-Life of…Candy” models nuclear decay and illustrates the idea of radioactive half-lives. It’s a neat and simple exercise that makes the point that even though any individual decay event is random, we can actually model radioactive decay with great accuracy for radioactive samples.

This activity is worth up to 4 LC BONUS points! Gather up some M&M’s, Skittles, coins or any other item that when tossed has a 50/50 chance of landing heads-up or tails-up. You will need at least 100 of the item that you choose. All of the items should be identical (i.e. if you use coins, make sure they are all the same type) To complete the assignment • Download the “HalfLifeData.xls” and the “HalfLifeAnalysis.rtf” files o “HalfLifeData.xls” is an excel spreadsheet that you can enter your data and make the graph. o “Half-LifeAnalysis.rtf” is an editable word processing file with some questions for you to answer. • Conduct 10 experimental trials as directed in the instructions on the next page. Record your data in the provided table. If you want – you can record your data directly into the spreadsheet, but it's always a good idea to have an original hard-copy of your data. • Enter your data into the HalfLifeData spreadsheet. The spreadsheet will construct your graph for you! Perform a "Save as…" on the spreadsheet and re-title the file as "lastname_HalfLifeData" • Complete the questions in the HalfLifeAnalysis file. Perform a "Save as…" on the file and re-title the file as "lastname_HalfLifeAnalysis" • Feel free to have a partner or two (three students maximum) from the class do the experiment with you. This is another great activity to share with Family. We did it as a family at home and it was more fun than a board game! • Submit your Data and Analysis files using the Dropbox on D2L to receive credit. You must submit completed copies of both files for credit. If you use candy, make sure to wash your hands before beginning and use clean containers/surfaces so you can eat your experiment when finished!

The Half-Life of….Candy

Instructions

1. Start with at least 100 items (M&M’s work great! Skittles or even coins would work too) 2. Pour out the items onto a flat surface (a small box works well to help contain the spill) 3. Each item that lands “heads up” represents an atom in the sample that has not decayed. 4. Remove the undecayed items and count them up. Record the number of “undecayed” items left after each half-life (1 half-life = 1 “pouring” of the items) on the data table below. 5. Remove the decayed items from the surface (or the box). 6. Pour the remaining undecayed items onto the surface or into the box and repeat steps 4-6 until you have no more undecayed items. A sample experimental trial from Dr.F., Beaker, and Spiff’s experiment is below. Yours will probably look similar, but not necessarily have the same values. Half-life number 1 2 3 4 5 6 7 8 9 10 1 49 22 10 7 4 3 0 8. Repeat the activity for 10 trials. Calculate the average number of undecayed items for each number of half-lives rounded to the nearest whole number. Data Undecayed Items Remaining after a Half-life 1 2 3 4 5 6 7 8 9 10 1 2

Trial Number

3 4 5 6 7 8 9 10 Average= 9. Use the HalfLifeData.xls file to graph your average value of undecayed items vs. number of half-lives. 10. Download and use the “HalfLifeAnalysis.rtf” file to analyze your results.

11. Save your files as directed and upload your data and analysis files to the D2L Dropbox...