Half life of radioactive Radon is 3.8, days . time at end of which 1/20^{th} of Radon sample will re

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13.Nuclei

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The half life of radioactive Radon is $3.8\, days$. The time at the end of which $1/20^{th}$ of the Radon sample will remain undecayed is ............ $days$ (Given $log_{10}e = 0.4343$ )

A

$3.8$

B

$16.5$

C

$33$

D

$76$

Solution

${\rm{N}} = {{\rm{N}}_0}{{\rm{e}}^{ – \lambda t}}$

and $t_{1 / 2}=\frac{\ln 2}{\lambda}, \quad N=\frac{N_{0}}{20}$

Standard 12

Physics

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