1. What shape (function) does the graph seem to follow? Does it agree with the expected theory for radioactive decay? 2. If you started with a sample of 600 radioactive nuclei, how many would remain undecayed after three half-lives? 3. How many half-lives would it take for 6.02 x 1023 nuclei to decay to 6.25% (0.376 x 1023) of the original number of nuclei? 4. Is there any way to predict when a specific piece of candy will land marked side up or "decayed?" If you could follow the fate of an individual atom in a sample of radioactive material, could you predict when it would decay? Explain. 5. Strontium-90 has a half-life of 28.8 years. If you start with a 10-gram sample of strontium-90, how much will be left after 115.2 years? Justify your answer. Toss # (hr) Number of Radioactive Nuclei Toss # (hr) Number of Radioactive Nuclei 0 80 9 3 1 50 10 2 2 34 11 2 3 19 12 1 4 8 13 1 5 5 14 0 6 4 15 7 8 33 16 17 Graph: Number of Radioactive Nuclei 90 80 70 60 50 40 30 20 10 0 Number of Radioactive Nuclei vs. Time 0 2 4 6 8 10 12 14 16 Time (Hr)