Recognition and classification of radioactive materials

Abstract

There is no simple way of telling if a piece of material is radioactive or not. You can’t smell radioactivity. This is fairly obvious but is probably worth emphasizing since radioactive material is very often shown to glow, in films and on television for example. In practice this just does not happen. A piece of radioactive aluminium will behave in exactly the same way as a piece of non-radioactive aluminium, except of course that it will emit radiation. Nor is there any relationship between the physical size of a piece of radioactive material and its activity. A small piece of material can be highly active, a large piece of material on the other hand may only be slightly radioactive or indeed inactive. This must be so since radioactive materials are made from inactive materials. In even a minute quantity of material there are so many nuclides that it is always possible to increase the number of active nuclides and hence to increase the activity.