# Who discovered radioactive dating

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.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.

Also, return to the questions you asked in the introduction to the lesson and allow students to revise their answers.The mathematics of inferring backwards from measurements to age is not appropriate for most students.They need only know that such calculations are possible. 79.) In this lesson, students will be asked to simulate radioactive decay by pouring small candies, such as plain M&M's® or Skittles®, from a cup and counting which candies fall with their manufacturer's mark down or up.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.Students should complete the Analysis section of the lab sheet, which will be used as part of their assessment.

Advise students to read through the simulation first so that they understand what they should do.

If you lived in a city where there had been a nuclear accident, you and your family might be exposed to strontium-90, which is the principal health hazard in radioactive fallout because it can easily get into the water supply or milk and then be ingested by people.

Write about how the strontium-90 might accumulate in your body (teeth and bones) and how it might affect you.

Include your ideas about how its half-life of 28.8 years would be important.

Suggest ways that government agencies, such as your state's department of health, might test for strontium-90.

To demonstrate that the rates of decay of unstable nuclei can be measured, that the exact time that a certain nucleus will decay cannot be predicted, and that it takes a very large number of nuclei to find the rate of decay.