Take Home Lab #3

Take Home Lab #3:  Half-Life Simulation

Question: What is the half-life of a simulated nuclear reaction?

Safety: Be careful with the scissors and keep them out of the reach of small children.

Materials: copy of provided paper, scissors, a box

Procedure: In this lab, you will simulate the graphing of the half-life of a radioactive substance using slips of paper. A half-life is defined as the time that it takes for half of a radioactive material to decay into another substance. You will simulate this process by flipping some papers and taking out all that are facing the same direction and continuing. The papers with the symbol facing down represent atoms that are radioactive. Those facing up have already decayed.

                Cut out all the pieces of paper with the Greek letter a (Alpha) on them. Put them in a box and shake them up. Take out all the pieces that have the a facing up. Count and record how many are left. Shake the box again, and again remove all of the pieces that have the a facing up. Count and record how many are left. Continue this until no pieces are left. Repeat this procedure one more time.

Data Table:

Trial number:	Number of papers left:
1	100
2
3
4
5
6
7

Prepare a graph with trial # on the x-axis and the number of papers left on the y-axis.

 

Papers

left

 

                                                Trial #

Post-Lab Questions:

1. How many shakes did it take to get rid of all the papers?

2. Use your graph to interpolate the half-life if each shake represents 1,000 years.

3. Use your graph to answer the question, “How many years have passed when 25% of the papers are left?”

4. According to your data, what is the oldest object that this method could be used to date?