Radioactive Decay/Half-Life

Sallie M. Fladger              John Hope Academy
                               5515 S. Lowe
                               Chicago, Illinois 60621
                               312-962-2760

Objective:

(for grades 3-12)

To demonstrate a model whereby students will perform a hands on application of 
determining the half-life of a radioactive element. 

Materials Needed:

The following materials are needed for each group of 2-4 students.         
  1)  corn candy                4) paper           
  2)  shoe boxes                5) pencil          
  3)  marker                    6) graph paper     
 
Instructors Preparation:

1) Have available shoe boxes for each group of 2-4 students.
2) Using the marker place an X at one end of the shoe box.
3) Place 100 pieces of corn candy in each box.
4) Diagram a model data table showing # of corn candy and # of years.
 
Procedures:
 
1) Make a data table as shown and make some predictions.
2) Remove the lid and empty corn candy into box.
3) Close the lid and shake the box gently 5 times.   
4) Remove the lid and remove all corn candy with the point
   facing the (X) inside of the box.
5) Count & record in the data table the number of corn candy
   left after each opening.
6) Repeat steps 3-5 until all of the corn candy is gone.
7) Graph the data from the data table onto graph paper,
   showing # of candy corn on the vertical & # of years on
   the horizontal.

Expected Results:

     Students should discover that after each shake (which represents years) & 
the removal of the corn candy (which represents atoms), there is a definite 
pattern of decay. 
     
     Students discover that it was impossible to predict when or how many corn 
candies would decay. 

Evaluation:

     The students' data table and graph curve will determine whether the 
students performed the experiment.