Nitrogen-13 has a half-life of 10 minutes.How much of a 128 mg sample would remain after 40 minutes?

Name: Nitrogen-13 has a half-life of 10 minutes.How much of a 128 mg sample would remain after 40 minutes?
Brand: Quizplus
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Question

Quizplus · Accepted Answer

Nitrogen-13 has a half-life of 10 minutes, so in 40 minutes, it will undergo 4 half-lives (40/10 = 4). After each half-life, the amount of substance is halved: 128 mg → 64 mg → 32 mg → 16 mg → 8 mg. Thus, 8 mg remains after 40 minutes.

Nitrogen-13 Has a Half-Life of 10 Minutes