1. USING RADIOACTIVITY
11.08

2. Uses of radioisotopes
Tracers: radioisotopes can be detected in very small and safe quantities, so they can be used as tracers in the following examples:
Checking the function of body organ
Tracking a plant’s uptake of fertilizers
Detecting leaks in underground pipes
Artificial isotopes with small half lives are used

3. Radiotherapy: Cobalt -60 is a strong gamma emitter
Radiotherapy: Cobalt -60 is a strong gamma emitter. A concentrated beam can be used to kill cancer cells
Testing cracks like X rays
Thickness monitoring of tyres
Carbon dating
Dating rocks

4. CARBON DATING
There are two isotopes of carbon in the atmosphere: 14C and 12C.
12C is stable but 14C is radioactive with a half life of 5000 yrs
However, it is made as quickly as it decays. So the ratio of 14C to 12C is always the same.
When the plants die, the 14C decays, so by measuring the ratio of 14C to 12C , the age of a piece of dead organic matter can be found.