The relation between $\lambda $ and $({T_{1/2}})$ is (${T_{1/2}}=$ half life, $\lambda=$ decay constant)
$\left(\lambda+ T _{1 / 2}\right)=\frac{ln }{2}$
$T _{1 / 2}=\frac{ln2}{\lambda}$
$T _{1 / 2}\; ln 2=\lambda$
$T _{1 / 2}=\frac{1}{\lambda}$
$x$ fraction of a radioactive sample decay in $t$ time. How much fraction will decay in $2t$ time
Write the definition of half life of radioactive substance and obtain its relation to decay constant.
Half lives of two radioactive substances $A$ and $B$ are respectively $20$ minutes and $40$ minutes. Initially the sample of $A$ and $B$ have equal number of nuclei. After $80$ minutes, the ratio of remaining number of $A$ and $B$ nuclei is
Given below are two statements :
Statement $I:$ The law of radioactive decay states that the number of nuclei undergoing the decay per unit time is inversely proportional to the total number of nuclei in the sample.
Statement $II:$ The half life of a radionuclide is the sum of the life time of all nuclei, divided by the initial concentration of the nuclei at time $t =0$.
In the light of the above statements, choose the most appropriate answer from the options given below :
Two radioactive materials $X_1$ and $X_2$ have decay constant $5\lambda$ and $\lambda$ respectively intially they have the saame number of nuclei, then the ratio of the number of nuclei of $X_1$ to that $X_2$ will be $\frac{1}{e}$ after a time