SP4d Half-Life Flashcards
What is half-life of a radioactive isotope?
it is the time it takes for half of its nuclei to decay into a more stable nuclei.
State 2 facts about half life.
.the half-life of a radioisotope remains constant over time
.different radioisotopes have different half-lives
What is the unit for radioactivity?
becquerel (Bq) - it is equivalent to one decay per second
What does the activity of a substance depend upon?
it depends upon the number of unstable nuclei there are in a sample and how unstable they are.
Why does activity decrease with time?
as unstable nuclei decay, there are fewer unstable nuclei left that could decay, which means that activity decreases with time.
Whats another way to define half-life?
time taken for the activity of a radioisotope to halve.
