Question

Iodine-131 is a radioactive isotope. After 8.00 days, 50.2% of the sample remains. What is the half life of 131-I?

Answer 1

ln(No/N) = kt
No = 100
N = 50.2
k = solve for this
t = 8 days

Then k = 0.693/t_1/2
Substitute for k and solve for t 1/2.

Answer 2

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