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Question

A radioactive isotope undergoes decay by emission of a positron. After 2.00 h, 5.880% of the initial amount of the isotope remains undecayed. What is the half-life of this isotope?
A) 45.0 min
B) 29.3 min
C) 90.0 min
D) 15.0 min
E) 60.0 min

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