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Starting with a sample of pure `^66Cu`, `3/4` of it decays into Zn in 15 minutes. The corresponding half-life isA. (a) 5 minutesB. (b) 7.5 minutesC. (c) 10 minutesD. (d) 3.5 minutes |
Answer» Correct Answer - B Decayed fraction is 3/4th. Therefore, left fraction is 1/4th. `N=N_0((1)/(2))^n` or `N/N_0=((1)/(2))^n=1/4` `:.` `n=` number of half-lives=2 Two half-lives are equivalent to 15 min. Therefore, one half-life is 7.5 min. |
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