Uses of Radioactivity

Carbon Dating

All living things contain carbon and a small fraction of this is unstable carbon 14. This means that all living things are radioactive. When the thing dies the amount of radiation it emits falls with time as this carbon 14 decays. By comparing the amount of radiation produced by the old object with that produced by something which has the same mass of carbon but is new we can calculate its age.

How old is this religious artifact? Carbon dating tells us about 500 years.	A Barium meal before an X ray gives a much better picture	Positron Emission Tomography is a fantastic new imaging technique
Geologists use radioactive tracers to look at underground water flow	Smoke alarms contain an alpha source.	Gamma radiation is used to kill cancerous cells

for many more uses look at  www.nsc.org/issues/rad/isotopes.htm