P4: HALF LIFE Flashcards
1
Q
What is half life?
A
-the time taken for the number of unstable nuclei in a sample to halve
or
-the time taken for the activity of a radioactive substance to halve
2
Q
What is activity?
A
the rate at which a radioactive source decays (measured in Becquerels (Bq))
3
Q
What is count rate?
A
no. of decays each second recorded by a G-M tube
4
Q
What is background radiation?
A
low level radiation that is all around which comes from:
-radioactivity from naturally occurring unstable isotopes
-radiation from space (cosmic rays)
-radiation due to human activity (eg: nuclear waste)
