Learning about atomic physics and radioactive decay can cause challenges as it requires students to describe and explain phenomena that they cannot see (decay) in terms of an atomic model that is also invisible to them. One approach, suggested by the University of Your Science Education group is to begin with exploring the effects of radioactive decay, move on to a qualitative macroscopic treatment considering what happens when radiation is absorbed. Then you move on to a quantitative macroscopic treatment covering content such as exposure, half-life and the drop of gamma intensity with distance. Once this has been covered then an explanation on an atomic level can be provided. Even if you don’t take this approach a secure understanding of the particle model is important and so is well worth revising.
The historical development of ideas provides an interesting narrative and this atomic model time line can help show the development of the model. Atomic structure, isotopes and ions can be supported with resources such as this interactive periodic table. Further exploration of electrons in different orbits and electrons changing orbit leads to emission and absorption spectra. Simulations, such as this one can help students visualise the random nature of decay. The terms contamination and direct irradiation are often confused by students and so care is needed when defining these terms.
There is an opportunity here to cover the maths skills by balancing equations, representing alpha-, beta- or gamma-radiations in terms of the masses, and charges of the atoms involved. As well as skills needed to calculate decays expressed as a ratio in a radioactive emission after a given number of half-lives.
In addition to the safety advice noted below, particular care and preparation is needed when handling radioactive sources and you should consult the designated school radiation protection supervisor before undertaking any practical work.
Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS, SSERC or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.