How many radioactive atoms are present in a sample that has an activity of 0.5 mCi and a half-life of 10 years? (1 curie = 3.7 × 10^10 decays/s)
a. 9.5 × 10^12 atoms
b. 8.4 × 10^12 atoms
c. 7.3 × 10^12 atoms
d. 6.5 × 10^12 atoms
e. 2.7 × 10^5 atoms
B
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