Question

The graph below shows radioactive decay of iodine.

Use the graph to determine the:-

1. Fraction of the amount remaining after 16.2 days.
2. Determine the half – life of iodine. 
3. Mass remaining after 17 days

Answer 1

1. 180/400( approx.)
2. T_½ = 7500 -2500 = 5000 years
    
3. No of halflifes = ¹⁵⁰⁰⁰/₅₀₀₀
   N1 =No(½)³
   100(½)³
   =12.5g