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Starting with a sample of pure .^66 Cu, ...

Starting with a sample of pure `.^66 Cu, 7//8` of it decays into `Zn` in `15 min`. The corresponding half-life is.

A

`15` minutes

B

`5` minutes

C

`7` minutes

D

`3.75` minutes

Text Solution

Verified by Experts

The correct Answer is:
B
`t = 1/lambda ln((N_(0))/(N)) rArr t = 1/(lambda) ln ((N_(0))/((N_(0))/(8))) rArr t = (3ln2)/(lambda)`
`tau = 3tau`
`15 = 3tau rArr tau = 5` minutes
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