Temperature and the activity of a radioactive source?
Teaching Guidance for 14-16
Effect of temperature and pressure on radioactive sources
Wrong Track: If you heat up a radioactive source, such as radium, it will become more active and give out radiation at a greater rate. It's just the same as with heating up chemicals in chemical reactions.
Right Lines: Changing the temperature of a radioactive source has no effect on the activity of the source.
Radioactivity is different from chemical change
Thinking about the teaching
The fundamental point to stress here is that external conditions, such as temperature and pressure, have no effect on the activity of a radioactive source. The spontaneous emission of radiation involves changes within the nucleus of each atom of the source. This is a different process from that involved in chemical changes where increasing the temperature results in increased motion of atoms, more frequent collisions and a consequent increased rate of reaction.