Homework SourseIodine 131 53I is used in diagnostic and therapeutic techniq
Iodine 131, 53I 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 131, 53 I remains after 44.5 days?
_______ %
_______ %
Solution
Decay constant k = ln(2)/half life
= 0.6931/8.04 = 0.08621 day-1
A/Ao = exp(-kt) where A is the amount remaining after time t, and Ao is the initial amount
= exp(-0.08621 x 44.5) = 0.0216
Percentage remaining = A/Ao x 100
= 0.0216 x 100 = 2.16%
