8.0k views
4 votes
2. Mercury-197 is used for kidney scans and has a half-life of 3 days. If 32 grams of

Mercury-197 is ordered, but takes 15 days to arrive, how much would arrive in this shipment?
Radioisotope:
Half life
Starting mass =
Final amount =
Starting time =
End time =
Half Life
Time
Mass (g)

1 Answer

7 votes

Answer:

1 grams Mercury-197

Step-by-step explanation:

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.

  • Note that, half life is the time taken by radioisotope to decay by half its original amount.
  • In this case, the half life of mercury-197 is 3 days, therefore, it takes three days for a mass of mercury-197 to decay by half its original mass.

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.

User KoKuToru
by
5.6k points