A report about the decay and half-life of different radioactive elements. It is impossible to predict when any one atom will decay but by looking at a number of atoms an average rate of decay can be calculated. The average time it takes for half the atoms in a large sample to decay is called the half-life.

This clip is from:
Bitesize: Physics
First broadcast:
20 March 2008

The clip could lead into discussion of measurement and safety of different elements and their half-lives. It could lead into a discussion of the example of carbon dating.