Given below are two statements: Statement I: The law of radioactive decay states that the number of nuclei…
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:
Both Statement I and Statement II are correct
Both Statement I and Statement II are incorrect
Statement I is correct but Statement II is incorrect
Statement I is incorrect but Statement II is correct
Solution
Both statements are incorrect.
As per law of disintegration, we have,
$\frac{d \mathrm{~N}}{d t}=-\lambda \mathrm{N}$
(where, the symbols have their usual meanings) Hence, $\mathrm{dN} \propto \mathrm{N}$, so the statement $\mathrm{I}$ is incorrect. $\mathrm{T}_{1 / 2}$ is the time in which active number of nuclei becomes half, so the statement II is also incorrect.