# Radioactive dating lab pennies from heaven, radioactive Dating Lab

## Demonstration of radioactive decay using pennies

Teaching Materials In a large class, give each student a penny. About how many students would have had to sit down if we started with twice as many students?

Do the same number of students sit down each time we flip the coins? This is based on information I have about the system.

The demonstration usually takes approximately minutes depending on how long it takes to count the students. What about if we only had half as many in this class? This can set up a good discussion of what is happening to the number of students still standing i. Half-life is the time it takes for half of a sample of an element to decay.

Shows students visually the concepts of exponential decay, half-life and randomness.

And finally, in the real world, uranium atoms don't have Abraham Lincoln on the front. They than compare the ratio of Nitrogen to Carbon in the fossil, and then can determine how many cycles of the half life the sample has run through. For example, I have eight Francium atoms.

It is a great way to introduce or reinforce the concepts involved in radioactive decay. How is radioactive decay sort of like gambling or playing the lottery? For question one, The pennies represent radioactive atoms, let's say, uranium. You will need enough coins I use pennies for each person in the class, some sort of graph paper printed on an overhead, free dating sites with no cost an overhead projector and a pen for the overhead. Some of them include handouts to use for homework in smaller classes.

## Radioactive Dating Lab

Can you predict which of you is going to be the first to sit down? Each flipping represents one cycle of an element's half life. References and Resources Here are links to several variations on this theme.