Radiometric dating.

Radiometric Dating from SERC

• http://serc.carleton.edu/NAGTWorkshops/time/activities/60525.html 
• http://serc.carleton.edu/quantskills/activities/MandMModel.html

You are going to be simulating the radioactive decay of an unstable isotope.   Any given atom of that isotope has a 50% chance of decaying over the course one half-life (the duration of which is a constant for any given isotope; i.e. about 5700 years for ¹⁴ C, about 700,000,000 years for ²³⁵U).  For this model, let’s assume that an M & M represents an atom.  If the side showing the letter “m” is up, the candy represents an undecayed atom of a radioactive isotope.  If the blank side is up, it represents a decayed atom (it has become another element).  A half-life is a single trial.

Objectives:

·        to understand the importance of the law of averages (thus sample size) on the proportion of undecayed-to-decayed atoms

·        to observe that the effect of decay in reducing the population size limits the number of half-lives to which the law of averages applies