1 grams Mercury-197
From the question,
The radioisotope is Mercury-197
The half life of Mercury-197 is 3 days
Starting mass is 32 grams
Time taken is 15 days
We are required to calculate the final mass of the radioisotope after 15 days.
Therefore, using the formula;
Final amount = Starting mass × (1/2)^n
where n is the number of half-lives (ratio of time to half life)
In our case, n = 15 days ÷ 3 days
           = 5
Therefore;
Final mass = 32 g × (1/2)^5
         = 32 g × 1/32
         = 1 g
Therefore, the amount of mercury-197 in the shipment that will arrive is 1 g.
