Uses Of Radioisotopes Flashcards
Recall industrial examples of the use of tracers
- to find dispersal of waste
- to find leaks/blockages in underground pipes
- to find the route of underground pipes
Where are alpha sources used in?
In some smoke detectors
What can radioactivity be used for?
To date rocks
Recall that some background radiation comes from waste products and man-made sources e.g. waste from:
- industry
- hospitals
Evaluate the relative significance of background radiaiton
Cosmic rays from outer space also contribute significantly to background radiation
Describe how tracers are used in industry
- radioactive material is out into pipe
- progress is tracked with detector above ground/outside pipe
- leak/blockage shown by reduction/no radioactivity after the point if blockage
Explain why gamma is used as an industrial tracer
Because gamma can penetrate through to the surface
Explain how a smoke detector with an alpha source works
- smoke particles hit by alpha radiation
- less ionisation of air particles
- current is reduced causing alarm to sound
What can measurements from radioactive carbon be used to find
The date of old materials
Explain how measurements if the activity of radioactive carbon can lead to an approximate age for different materials
- the amount of Carbon-14 on the air has not changed for thousands of years
- when an object dies (e.g.wood) gaseous exchange with the air stops
- as the Carbon-14 in the wood decays the activity of the sample decreases
- the ratio of current activity from living matter to the activity of the sample is used to calculate the age within known limits
Explain how the radioactive dating of rocks depends on the calculation of the unpranium/lead ratio
Thos is because the ratio tells us how long the rock has existed for
Understand why background radiation can vary
It can vary depending on the rocks in the area
