Radioactive Decay and Activity?
February 242010
Iodine 131 over 53(i) is used in diagnostic and therapeutic techniques in the treatment of thyroid disorders. This isotope has a half-life of 8.04 days. What percentage of an initial sample of remains after 36.5 days?
_______%
After 8.04 days 1/2 of it remains
after 16.8 days 1/4 remains
after 24.84 days 1/8 remains
and so on….
How do you figure how much remains after 36.5 days?
the fraction remaining will be given by
A/Ao = e^(-0.693t/T)
where
Ao = the original amount
T = the half life
t = the time
A = the amount left after time t
e = the exponential function
For this problem
A/Ao = e^(-0.693*36.5/8.04) = 0.043020347
A = 4.3 % of Ao
February 24th, 2010 at 2:42 pm
After 8.04 days 1/2 of it remains
after 16.8 days 1/4 remains
after 24.84 days 1/8 remains
and so on….
How do you figure how much remains after 36.5 days?
the fraction remaining will be given by
A/Ao = e^(-0.693t/T)
where
Ao = the original amount
T = the half life
t = the time
A = the amount left after time t
e = the exponential function
For this problem
A/Ao = e^(-0.693*36.5/8.04) = 0.043020347
A = 4.3 % of Ao
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