Ios 7 Article

8.01 Lab Report
FLVS

The purpose of this hands-on lab is to model the concept of half-life using a sample to represent radioactive atoms.
Materials
200 M&M® candies, pennies, or other small candy/item with two distinct sides shoe box or other small box with a lid
Procedure
1. Place 200 candies in the shoe box, lettered sides up. The candies will stand for atoms of a hypothetical radioactive element.
2. Cover the box and shake it vigorously for three seconds. This is one time interval.
3. Remove the lid and take out any candies (atoms) that have that are now showing lettered sides down. These candies represent the atoms that decayed during the time interval. Count and record in a data table the number of decayed atoms and the number of remaining, not decayed, atoms.
4. Continue repeating steps two and three until all atoms have decayed or you have reached 30 seconds on the data table.
5. Repeat the entire experiment (steps 1–4) a second time and record all data.
Data and Observations
Create and complete a data table, like the one below, for each trial.
Time (seconds)
Radioactive atoms remaining (not decayed)
Atoms decayed
0
200
0
3 178 22
6
165 13
9
156 9
12
141 15
15
110 31
18
103 7
21
76 27
24
60 16
27
56 4
30
45 11
Calculations
Trial 2;
Time (seconds)
Radioactive atoms remaining (not decayed)
Atoms decayed
0
200
0
3 194 6
6
157 37
9
133 24
12
126 7
15
116 10
18
110 6
21
92 18
24

12
27

9
30

4

1. Determine the average number of atoms remaining (not decayed) at each three-second time interval by adding the results from the two trials and dividing by two.
2. Create a table that compares time to the average number of atoms remaining at each time interval.
3. Create a graph of your data showing the average number of atoms remaining versus time.
Conclusion
Answer the following questions in complete sentences.
1. After how many time