Chemistry of radioactive dating
Have them go directly to the Nuclear Structure Systematics Home Page.
Once to that page, students should then go to the Isotope Discovery History, a graph of the number of known isotopes versus the date, and to the Chart of Aristotle and Plato (found at the bottom of the page), which the site planners cleverly call "the first chart" of isotopes.
"Today we will simulate radioactive decay to understand what we mean by half-life.
Radioactive decay, also known as radioactivity, is the spontaneous emission of radiation from the unstable nucleus of an atom." Have students go to the Isotopes Project website to look for more information about radioactive decay.
You may group them in any size, but working in pairs is optimal for this exercise.
Weigh out 80 candies for each group into cups before students arrive, as described in the Planning Ahead section above.
Have students look at the Glossary of Nuclear Science Terms for alpha and beta decay.
In addition to using answers to students' analysis questions and their graphs for assessment, consider having them respond to the following in their science journals or as a homework assignment: Strontium is chemically similar to calcium.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.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.It may be combined with the Frosty the Snowman Meets His Demise: An Analogy to Carbon Dating, which can be done while students are flipping their candies.In your planning, be sure to include time at the end of the lesson for students to post their data and share the class data.
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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.