Multiple Choice
The isotope 
has a half-life of 7.5 seconds. If a sample contains 144 atoms of 
approximately how many such atoms were there present 30 seconds earlier?
A) 576
B) 1152
C) 2304
D) 4320
E) 4.30 × 10 8
Correct Answer:
Verified
Correct Answer:
Verified
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