$_{11}Na^{24}$ has a half-life of $15 \ h$. On heating,its half-life will:

If $2.0 \ g$ of a radioactive isotope has a half-life of $20 \ hr$,the half-life of $0.5 \ g$ of the same substance is ........ $hr$.

During a nuclear explosion,one of the products is $^{90}Sr$ with a half-life of $6.93 \; \text{years}$. If $1 \; \mu g$ of $^{90}Sr$ was absorbed in the bones of a newly born baby in place of $Ca$,how much time,in years,is required to reduce it by $90 \%$ if it is not lost metabolically?

What is the value of the decay constant of a compound having a half-life time $T_{1/2} = 2.95 \text{ days}$?

The decay constant of a radioactive sample is $\lambda$. The half-life and mean life of the sample are respectively

$A$ radioactive sample decays to half of its initial concentration in $6.93 \ min$. It further decays half in next $6.93 \ min$. The rate constant for the reaction is ..... $\min^{-1}$