A 50-mg sample of iodine-131 was placed in a container 32.4 days ago.If its half-life is 8.1 days,how many milligrams of iodine-131 are now present?

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Quizplus · Accepted Answer

The amount of iodine-131 remaining after a certain number of half-lives can be calculated using the formula: remaining amount = initial amount * (1/2)^(time elapsed / half-life). Here, the initial amount is 50 mg, the time elapsed is 32.4 days, and the half-life is 8.1 days. Thus, the number of half-lives = 32.4 / 8.1 = 4. Therefore, the remaining amount = 50 * (1/2)^4 = 50 * 1/16 = 3.125 mg, which is approximately 3.1 mg.

A 50-Mg Sample of Iodine-131 Was Placed in a Container