The presenters recap on atomic structure by defining an element's atomic number and mass number. They then use protons and neutrons to make a model of a francium nucleus. The nucleus is unstable and starts to decay. The presenters point out the three different types of radiation that are being emitted.
This clip could be used by students as an introduction to radioactivity. The clip needs to be used in conjunction with 'Introduction to radioactivity (pts 2/3 and 3/3)'.