Introduction:Half-life is the time required for one half of a radioactive material to decay or change into something else. Radioactive atoms have nuclei that are unstable. These nuclei become more stable by emmitting particles or rays. The half-life of an isotope is characteristic of that isotope. The value can be from fractions of a second to billions of years. Half-life values are constant - there is no way to speed up or slow down this natural process.Purpose:
The purpose of this experiment is to simulate the process of radioactive decay and determine the "half-life" for the process.Materials:
-plastic sandwich bag of M & Ms-paper plate
Procedure:
Each M & M will represent at atom of a radioisotope. The M & Ms in the baggie are thoroughly mixed and poured out onto the paper plate. Those M & Ms with letters showing are still "radioactive". The others have "decayed" and should be removed (eaten). Count the numbers of "atoms" that remain, and record the values in the data table. Return those M & Ms which have the letters showing to the bag, shake, and pour onto the paper plate. Again, count the number of M & Ms with letters still showing. Record and continue. When the data has been collected, plot the data (atoms left vs. trial number) and draw a smooth curve through the points.
The value for the half-life is obtained as follows:1. Select two values on the y-axis. One value should be twice as large as the other (60 & 30 for example).
2. Draw lines from these points to your line.
3. Next, vertical lines should be drawn from where these lines intersect your lines to the x-axis. The space between these lines on the x-axis is the half-life. What these lines tell us is that half of the radioisotope has decayed and this is the amount of time that is required for it to happen.
Data:Original Number of Atoms _______________