The half lives of a radioactive substance are $T$ and $2T$. years for $\alpha - $ emission and $\beta - $ emission respectively. The total de cay constnnt for simultaneous decay of $\alpha$ and $\beta$ adioactive substance is ___
$\frac{3}{2}\frac{{\ln 2}}{T}$
$\frac{{3\ln 2}}{T}$
$\frac{{\ln 2}}{3T}$
$\frac{2}{3}\frac{{\ln 2}}{T}$
Draw a graph of the time $t$ versus the number of undecay nucleus in a radioactive sample and write its characteristics.
The half-life of a radioactive nucleus is $5$ years, The fraction of the original sample that would decay in $15$ years is
A element used for radioactive carbon dating for more than $5600$ years is
A radioactive sample has half-life of $5$ years. Probability of decay in $10$ years will be ........$\%$
In a sample of radioactive material, what percentage of the initial number of active nuclei will decay during one mean life .......... $\%$