Using Radioactive Sources Flashcards
Why can’t we predict which nucleus will decay first
Due to the randomness of radioactive decay
What IS possible to predict
How many nuclei will decay in a certain time period
What is the half life of a radioactive isotope
The average time it takes half of the nuclei to decay
The time it takes for the count rate,or activity of a sample containing the isotope to fall 50% of its original value
What are the features of isotopes with a long half life
The isotopes are very unstable and emot radiation quickly so exposure can be hazardous
Do not email radioactive very long
What are the features of isotopes with a long half life
They are more stable and remain radioactive for a very long time
Emit radiation slowly so exposure is less hazardous
What are medical tracers used to do
Look at internal organs
How do medical tracers work
A radioactive isotope is ingested or injected into the body
As it travels round the body it can be detected from the outside
How could medical tracers help monitor kidney function
An isotope that will pass through the kidneys is used
If it builds up in one kidney and not the other this could indicate one kidney is not working efficiently
How can medical tracers help intestines
If there is a blockage the. Radioactivity cannot be detected after the blockage
If the intestines are damaged the radioactive source can be seen to pass out of the intestines into other areas of the body
How can rumours be treated by nuclear radiation
A rumour in the thyroid gland could be treated with radioactive iodine which gathers the gland and destroys nearby cells
A focused beam of gamma rays could destroy some tumours
Why would a gamma source make the best tracer
They can penetrate the body and he detected on the outside
They are the least ionising
