Half life period of a radioactive sample is $T$. Let $x$ fraction disintegrates in time $'t'$. How much fraction will decay in $'\frac{t}{2}'$ time
$\left( {\frac{x}{2}} \right)$
$\left( {\frac{x}{{\sqrt 2 }}} \right)$
$1 - \left( {\frac{x}{{\sqrt 2 }}} \right)$
$1 - \left( {\sqrt {1 - x} } \right)$
In a radioactive sample, ${ }_{10}^a K$ nuclei either decay into stable ${ }_{20}^{* 0} Ca$ nuclei with decay constant $4.5 \times 10^{-10}$ per year or into stable ${ }_{18}^{40}$ Ar muclei with decay constant $0.5 \times 10^{-10}$ per year. Given that in this sample all the stable ${ }_{20}^{\infty 0} Ca$ and ${ }_{15}^{20} Ar$ nuclei are produced by the ${ }_{19}^{* 0} K$ muclei only. In time $t \times 10^{\circ}$ years, if the ratio of the sum of stable ${ }_{30}^{40} Ca$ and ${ }_{15} \operatorname{An}$ nuclei to the radioactive ${ }_{19} K$ muclei is $99$ , the ralue of $t$ will be : [Given $\ln 10=2.3]$
If $t_{1/2}$ is the half life of a substance then $t_{3/4}$ is the time in which substance
Half-life of a substance is $10$ years. In what time, it becomes $\frac{1}{4}\,th$ part of the initial amount ........$years$
An archaeologist analyses the wood in a prehistoric structure and finds that ${C^{14}}$ (Half life $= 5700\, years$) to ${C^{12}} $ is only one- fourth of that found in the cells buried plants. The age of the wood is about ........$years$
The decay constant of the end product of a radioactive series is