A radioactive source has a half-life of 8.0 hours and an initial activity of 800 Bq. What is the activity after 24 hours?
Answer and explanation
Correct answer: A. 100 Bq
- Step 1: 24 hours is 3 half-lives. Step 2. Bq. Answer: 100 Bq. Why not the others: 267 Bq divides by 3; 400 Bq is the activity after one half-life; 200 Bq is the activity after two.
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