Radioactive decay
Let the number of nuclei (dN) in a radioactive source decaying in a short time dt be dN.
dN is proportional to:-
N - the number of radioactive nuclei present at that moment
dt - the time over which the measurement is made
the element, represented by a constant (l) called the disintegration (or decay) constant
dN = - lNdt space Activity: dN/dt = - lN |
The activity is measured in units called Becquerels (Bq) where 1 Bq = 1 disintegration per second.
The disintegration constant or decay constant (
l) can be defined as the probability of a nucleon
decaying in the next second.
Number of nuclei (N) = Noe-lt space Activity (A) = Aoe-lt space Mass (m) = moe-lt
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A useful alternative formula for radioactive decay is: A = A
o/2
n where n is the number of half lives that have passed and A
o and A are the original and final activities.