But the ans is 1/2..
Radium(Atomic no. 87 and mass no.221) is a radioactive substance having half life of 4 days.Find the probability that a nucleus undergoes decay after two half lives.
A.1
B.1/2
C.3/4
D.1/4

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2 Answers
Shaswata Roy
·20140103 07:44:19
After 2 half lives the amount decayed would be =
\left(1\frac{1}{2^2}\right)N_0=\frac{3}{4}N_0
Hence the probability that a nucleus had decayed in this time interval= Amount decayedInitial amount=34