Half-life experiment

Half the class will use the data from the GM-tube and half will collect data from the scintillator.

There are several runs of the test: we will get different groups to collect data from different runs

Trial 1, trial 2, trial 3, trial 4, trail 5

1. Take down the background radiation readings for your instrument.

2. Write down which trail you are doing

3. Decide with your partner how frequently you will take your data.

4. Use the prepared excel spreadsheet to enter your values. (GM-tube sheet, scintillator sheet: Watch these spreadsheet explanations: Part 1, Part 2)

5. Determine the activity for each interval you measured

6. Plot a time vs activity graph.

Discussion:

• 1. Why do we use a midpoint for the time interval?

  2. Why do we plot the activity rather than the counts?

Compare the plot and data from the GM tube and the scintillator

• 1. How are they the same?

  2. How are they different?

Use the graph to determine the half life of your trial. Enter your data onto this slide show

• 1. How does your data compare to the other trails?

  2. Look up the known half-life for barium 137m and compare your data and the other instrument data and explain the variation.

  3. How could this analysis be improved?

  4. How could the experiment be improved?