Although quantitative measurements in radioactivity teaching and research are only believed to be
possible with high technology, early work in this area was fully accomplished with very simple
apparatus such as zinc sulphide screens and electroscopes. This article presents an experimental
practice using the electroscope, which is a very simple apparatus that has been widely used for
educational purposes, although generally for qualitative work. The main objective is to show the
possibility of measuring radioactivity not only in qualitative demonstrations, but also in
quantitative experimental practices. The experimental set-up is a low-cost ion chamber connected to
an electroscope in a configuration that is very similar to that used by Marie and Pierre Currie,
Rutherford, Geiger, Pacini, Hess and other great researchers from the time of the big discoveries in
nuclear and high-energy particle physics. An electroscope leaf is filmed and projected, permitting
the collection of quan…