Half Life Lab
Half-Life of M&Ms
Introduction
Half-life is the time required for something to fall to half its initial value. The half-life of a radioactive element is the time it takes for half of its atoms to decay into something else. M&Ms were chosen because they all have the same m mark on the on one side. In this lab you will go through predicting and counting the number of remaining "mark-side up" candies that should help understand that rates of decay of unstable nuclei and how it can be measured; that the exact time that a certain nucleus will decay cannot be predicted; and that it takes a very large number of nuclei to find the rate of decay.
Purpose
To stimulate the transformation of a radioactive isotope with M&Ms over time and to graph the data and relate it to radioactive decay and half-lives.
Materials and Safety
Materials * 200 pieces of M&Ms (trademark only) * Shoe Box * Pen/Pencil * Paper Towel
Safety- No safety precautions needed
Procedure 1. Count out 200 M&Ms. Place all 200 candies in the shoe box with the letter facing up 2. Cover the box and shake it vigorously for 3 sec. This is 1 time interval. 3. Remove the lid and take out any atoms (candies) that have “decayed”, that is, that are now showing lettered sides down. Record on the data table the numbers of decayed and remaining atoms. 4. Replace the cover on the box, and shake for another 3-sec time interval. Record the number of “radioactive’ atoms remaining. 5. Keep repeating time interval trials until all atoms have decayed or you have reached 30 sec on the data table 6. Repeat the whole experiment a second time, and record all data. 7. Average the number of atoms left at each time interval from both trial. Make a graph of your data showing the average number of atoms remaining versus time
Data Table
Data Table
Results
Trial 1
Introduction
Half-life is the time required for something to fall to half its initial value. The half-life of a radioactive element is the time it takes for half of its atoms to decay into something else. M&Ms were chosen because they all have the same m mark on the on one side. In this lab you will go through predicting and counting the number of remaining "mark-side up" candies that should help understand that rates of decay of unstable nuclei and how it can be measured; that the exact time that a certain nucleus will decay cannot be predicted; and that it takes a very large number of nuclei to find the rate of decay.
Purpose
To stimulate the transformation of a radioactive isotope with M&Ms over time and to graph the data and relate it to radioactive decay and half-lives.
Materials and Safety
Materials * 200 pieces of M&Ms (trademark only) * Shoe Box * Pen/Pencil * Paper Towel
Safety- No safety precautions needed
Procedure 1. Count out 200 M&Ms. Place all 200 candies in the shoe box with the letter facing up 2. Cover the box and shake it vigorously for 3 sec. This is 1 time interval. 3. Remove the lid and take out any atoms (candies) that have “decayed”, that is, that are now showing lettered sides down. Record on the data table the numbers of decayed and remaining atoms. 4. Replace the cover on the box, and shake for another 3-sec time interval. Record the number of “radioactive’ atoms remaining. 5. Keep repeating time interval trials until all atoms have decayed or you have reached 30 sec on the data table 6. Repeat the whole experiment a second time, and record all data. 7. Average the number of atoms left at each time interval from both trial. Make a graph of your data showing the average number of atoms remaining versus time
Data Table
Data Table
Results
Trial 1