Set Up
Procedure
The diagram/table below shows this process if you started with 30 dice DataFor each roll, students count up the number of newly decayed and record the totals in a data table. There is space in the lab for 20 rolls. In my experience, that is enough to get them to a point where either all dice have "decayed" or it's close enough that the students get the idea. GraphOne of the main objectives for this lab is to provide students with an opportunity to create a half-life curve from real data. In the pdf, students are provided with a preset axes to graph both the "total undecayed" and the "total decayed" by hand. The dotted lines placed at 100, 50, 25, and 12.5 dice are to help students use the graph to estimate the half-life observed in their lab data. By fitting a curve to the data and marking where that line intersects these dotted lines, the half-life of the "radioactive" dice is just the average horizontal spacing between the marks. QuestionsThe lab concludes with a series of analysis questions that connect the lab with the traditional half-life problem solving examples that students should know how to do. For example:
ExtensionsWhile not captured in the write up, one of my favorite discussions that comes out of this data is how we actually measure the radioactive half life. Even though we often graph the total number of atoms that are "decayed" or "undecayed", that isn't a value that is easily measured in real life. Instead, the true data is more analogous to the "newly decayed" column. It is the number of events per unit of time that can be measured with geiger counter to see how the activity changes over the lifespan of the element. Some groups even noticed this on their own by making a "graph" using the decayed dice from each round :) Materials - 3D Printed
These models are posted for free in the standard places if you want to print your own or I have the option to purchase these kits premade and shipped to you in any colors that you want. Everything can be found in the link below :) CLICK HERE for 3D Printed Models/KitsMaterials - HomemadeWhile it looks really cool and I think my students definitely appreciated it, the fancy die design isn't really required to do this lab. You can also do a similar investigation with standard 6-sided dice and just modify the language in the lab so that they are looking for a six (or any number that you decide should indicate that the atom has decayed). If you want to make it more permanent, you could even use a sharpie to color one side of each die to make it easier to spot. If you build your own kits in this way, you will just need to buy LOTS of dice so that each group can get 100 :) Files
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