Half life dating
Comparing that to the half-life of the nuclei tells when they started to decay and, therefore, how old the object is.Archaeologists use the exponential, radioactive decay of carbon 14 to estimate the death dates of organic material.At any particular time all living organisms have approximately the same ratio of carbon 12 to carbon 14 in their tissues.When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to nitrogen 14 changes the ratio of carbon 12 to carbon 14.
After 5,730 years, the amount of carbon 14 left in the body is half of the original amount.
This experiment is best used by student working in pairs.
Grade Level: 5-12 grade Disciplinary Core Ideas (DCI) 3-5ETS1-2, MS-ESS1-4, HS-ESS1-6 Time for Teacher Preparation 40-60 minutes – To gather materials Activity Time: 40-60 minutes (1 Class Period) Materials: Objectives Students try to model radioactive decay by using the scientific thought process of creating a hypothesis, then testing it through inference.
By extension, this experiment is a useful analogy to radioactive decay and carbon dating.
Students use M&M’s (or pennies and puzzle pieces) to demonstrate the idea of radioactive decay.