Carbon dating demonstration
It is a great way to introduce or reinforce the concepts involved in radioactive decay.
You will need enough coins (I use pennies) for each person in the class, some sort of graph paper printed on an overhead, an overhead projector and a pen for the overhead.
Plants and animals assimilate carbon 14 from carbon dioxide throughout their lifetimes.
When they die, they stop exchanging carbon with the biosphere and their carbon 14 content then starts to decrease at a rate determined by the law of radioactive decay.
Oxidizable carbon ratio dating is a method of dating in archaeology and earth science that can be used to derive or estimate the age of soil and sediment samples up to 35,000 years old.
The method is experimental, and it is not as widely used in archaeology as other chronometric methods such as radiocarbon dating. Pollan 1995 Excavations at Site 41WH24, Wharton Co., Texas.
Archaeology and other human sciences use radiocarbon dating to prove or disprove theories.
A buffalo tooth rests in a tube of the Low Energy Plasma Radiocarbon Sampling machine located in the New Mexico Office of Archaeological Studies lab.The demonstration usually takes approximately 5-10 minutes depending on how long it takes to count the students.If your class is particularly large, you might want to have a few students help you count the "undecayed" isotopes.This demonstration is a great way to break up the lecture with a short activity – students get to stretch their legs.I often give students the penny at the beginning of class with no explanation – or say something like, "Today, you're getting paid for coming to class!
" After introducing some of the concepts involved in radioactive decay, I do the demonstration. Tell them that they will be flipping the penny (you will tell them when); each time they flip one half life will have passed.