How Many Radioactive Atoms Are Present in a Sample That

question 36

Multiple Choice

How many radioactive atoms are present in a sample that has an activity of 0.5 μCi and a half-life of 10 years? (1 curie = 3.7 × 10¹⁰ decays/s)

• A) 9.5 × 10¹² atoms
• B) 8.4 × 10¹² atoms
• C) 7.3 × 10¹² atoms
• D) 6.5 × 10¹² atoms
• E) 2.7 × 10⁵ atoms

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