AP Physics 2‎ > ‎Unit 6‎ > ‎Nuclear Decay‎ > ‎

Half-Life Lab

Half-Life Lab


In this activity you will be working to find the decay constant and half-life for an isotope with a relatively short half-life


  1. For this program you will be collecting data for a 10 second time interval that are spaced 1 minute apart.  So you data table will look like this:

     Total Time (s) Counts in 10 seconds

  2. Open up the program found here.

  3. Clicking on the activity in the upper left corner of the lab will give you a fresh sample of your isotope.  Find the sample with the greatest activity and use it for your lab.

  4. Your isotope will be decaying the moment you create it, so be prepared as to what you must do to properly collect your data.

  5. Allow your decade counter to count radioactive decay particles for 10 seconds and then hit the "hold button".   In your data table record this as time = 0 and counts equal to your counts for that 10 second interval.

  6. Allow the program to continue to run until the total time reaches 60 seconds.  At this point, you want to reset the decade counter and collect data for another 10 seconds.  In your data table record this as time = 60 and counts equal to your counts for that 10 second interval.

  7. Continue to collect 10 s worth of data at the start of each new minute until you have collected a total of 10 data points.

  8. Use this program to plot a graph of  Counts vs. Time (s) and curve fit it with an exponential function.
Stuff to have in your lab book:
  1. Purpose

  2. A labeled picture of the lab setup

  3. Data Table

  4. Graph and equation

  5. A three paragraph conclusion.

    1. Paragraph 1 gives your purpose and a summary of your procedure.

    2. Paragraph 2 gives your results.

    3. Paragraph 3 gives possible sources of error and methods to correct these errors.