On a process level, the student will be using the scientific method to test and observe the pattern of the coin sample and extrapolate the” half life “of the coin sample from the obtained data.Hopefully, the result is a clear- cut operational concept of the half- life of radioactive substances.Later, students applied this knowledge to determine the ages of a series of rocks and organic remains represented by bags of Froot Loops™.Various colors were used to indicate parent and daughter isotopes of several elements with different half-lives.In a large collection of atoms, there is a definite time, called the half-life of the isotope, after which one-half of the total number of nuclei would have decayed.This time varies from few-millionths of a second to millions of years for different radioactive isotopes.Half lives can be as short as milliseconds and as long as billions of years.
The first two authors developed a unit to correct 8th grade students’ misconceptions and to foster interest in radioactive decay and radiometric dating.
On the information level, the student will be using concrete, hands on model to demonstrate the meaning of half –life in the process of radioactive decay.
The chances that a single atom of uranium -238 will decay during a one minute period are indeed very low.
Students often have difficulty comprehending these topics and hold a variety of misconceptions.
Specific examples from our experience include: absolute dating provides error-free ages; decay rates could be affected by the sample age, composition or environment; radioactive isotopes decay into nothing; half-life is half the life of an atom; and half lives are the same for all atoms.