Definition of radioactive dating
This is the second lesson in a three-lesson series about isotopes, radioactive decay, and the nucleus.
The first lesson, Isotopes of Pennies, introduces the idea of isotopes.
The final lesson, Frosty the Snowman Meets His Demise: An Analogy to Carbon Dating, is based on gathering evidence in the present and extrapolating it to the past.
To do this lesson and understand half-life and rates of radioactive decay, students should understand ratios and the multiplication of fractions, and be somewhat comfortable with probability.
Include your ideas about how its half-life of 28.8 years would be important.After one half-life, half of the nuclei will have disintegrated, leaving 50 nuclei." Have students write their answers to these questions in their science journals.At the end of the lab, give them the opportunity to revisit these questions and change or justify their answers.This method of measuring a rate won't work for radioactive decay.
We know that radioactive substances disintegrate at a known rate, however. It is the length of time required for the disintegration of one-half of a given number of nuclei of a radioactive element. Suppose we have 100 nuclei of a radioactive isotope.
Games with manipulative or computer simulations should help them in getting the idea of how a constant proportional rate of decay is consistent with declining measures that only gradually approach zero.