Question #705ba

1 Answer
May 4, 2017

Answer:

Activity after 75-yrs => 16.53% of original activity remains.

Explanation:

All radio-isotope decay is 1st order kinetics and follows the classic 1st order decay trend described by #A_"(final)" = A_"(initial)"e^-"kt"# ; A = Activity, k = decay constant, t = time. The half-life equation can be used to calculate decay constant => #k = (0.693/t_"1/2")# The initial activity = 100%, t = 75-yrs.

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