Lab 7: Radioactivity
INSTRUCTIONS:
• On your own and without assistance, complete this Lab 7 Answer Form and submit it via the Assignments Folder by the date listed on your Course Schedule (under Syllabus).
• To conduct your laboratory exercises, use the Laboratory Manual that is available in the classroom. Laboratory exercises on your CD may not be updated.
• Save your Lab 7 Answer Form in the following format: LastName_Lab7 (e.g., Smith_Lab7).
• Submit your document in a Word (.doc or .docx) or Rich Text Format (.rtf) for best compatibility.
Experiment 1: Estimating Half-Life
Table 2: Half-Life Experimental Results
Total number of atoms:
Trial Number of decayed atoms Average Percentage of decayed atoms (from original number)
1st Round 2nd Round 3rd Round
1
2
3
4
5
6
7
8
9
10
Questions
1. What is meant by the term half-life?
2. At the end of two half-lives, what percentage of atoms (Skittles™) have not decayed? Show your calculation.
3. Using your data, graph the number of undecayed atoms vs. trials below to show when 1/2, 1/4, 1/8, and 1/16 of your Skittles remain (use the values next to the boxes you put checks next to in Step 8 of the procedure).
4. How would the graph change if 20 Skittles were used in this experiment?
5. If 1/8 of a radioactive element remains after 600 years, what is that element’s half-life?
Learning Summary
1. Please include a brief one Paragraph Learning Summary that described what you thought the main take-aways were for the lab and what you think that you learned by doing this experiment.
