Topic 4 - atomic structure ( 4. activity and half life ) Flashcards
what can radiation be measured with
geiger muller tube
how can you find out the amount of radiation emitted by a sorce to half
calculating the half life
what is activity
the rate at which a source decays which can be found by calculating the half-life
what is activity measured in
becquerels(1 bq is 1 decay per second)
why do we use the idea of half life
the problem with measuring the activity is that the activity never reaches 0.
what is half life
half-life is the time it takes for the number of nuclei of a radioactive isotope in a sample to halve.
what is another definition for half life
time it takes for the count rate or activity from a sample containing the isotope to fall to half its initial lever
what does it mean when the isotope has a short half life
activity falls quickly, because the nuclei are very unstable and rapidly decay. these sources can be dangerous
what does it mean when the isotope has a long half life
slower as the nuclei don’t decay for a long time. this can be dangerous because nearby areas are exposed to radiation for long amounts of time.