Alpha decay generally has the longest half-life. Teach students about half-life with a simple lab. Place 50 pennies in a shoebox to represent atoms. Cover the shoebox, and shake for 10 seconds. Remove the decayed atoms (or tails-up pennies), and enter the number of decayed and undecayed atoms on a chart with four columns: half-life (shake number), time, undecayed atoms (heads up), decayed atoms (tails up). Repeat the process, recording the data until all atoms are decayed. Ask students to use the chart to determine what percentage of atoms decayed at each half-life. This activity can be recreated with 50 dice in which each roll represents a half-life and a roll of one represents a decayed atom.
Colored candy can be used to represent radioactive decay for students. Pass around a jar that contains two colors of candy. Choose one color to represent decayed atoms and the other color to represent undecayed atoms. Ask students to close their eyes and pick a piece of candy from the jar. If the candy is decayed, it stays out of the jar. It if it is undecayed, it goes back into the jar. Students will notice that it gets harder to find decaying atoms as the jar is passed around.
PhEt, a resource provided by the University of Colorado at Boulder, offers online simulations of alpha decay and beta decay. These simulations are ideal for display on an interactive whiteboard to show an entire class how alpha particles escape from a nucleus to cause alpha decay or can be used by individual students to review the concepts. Sharing the beta decay simulation with students gives them something to compare alpha decay to and deepens their level of understanding.
The Java-based "Radioactive Dating Game" offered by PhEt asks students to measure the age of objects underground based on the percentage of dating element that remains through the process of radiometric dating. This game can be confusing for students with no knowledge of alpha decay or radioactive dating, so teachers should model how to play the game and provide some background information before asking students to play it on their own.