How many half-lives pass when a 100-mg medication has been used, and only 6.25 mg remain?
A)2
B)3
C)4
D)None of the above

Question

Quizplus · Accepted Answer

Each half-life reduces the quantity of the substance by half. Starting with 100 mg, after one half-life, 50 mg remains; after two, 25 mg; after three, 12.5 mg; and after four, 6.25 mg. Thus, four half-lives pass to reduce the medication from 100 mg to 6.25 mg.

How Many Half-Lives Pass When a 100-Mg Medication Has Been