If 160. mg of fluorine-18 is shipped at 8:00 A. M., how many milligrams of the radioisotope are still active when the sample arrives at the radiology laboratory at 1:30 P. M.?

Explanation:

Two important equations in radioactive decay are

We can use them to solve this problem.

1. Calculate the radioactive decay constant

The half-life of ¹⁸F is 109.8 min.

(ii) Calculate the mass of ¹⁸F remaining

Time in transit  = 13:30 - 08:00 = 05:30 h = 5.50 h = 330 min

the answer is learned

increased stability in the completion of fluorine's outer shell.