Answer: The correct answer is Option B.
Explanation:
We are given a radioisotope which is unstable in nature. For this isotope to become stable, it has to undergo radioactive decay. There are various processes by which a radioisotope may decay:
1. Alpha decay: In this decay process, a heavier nuclei decays into lighter nuclei. The particle released is alpha particle.
[tex]_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}\textrm{Y}+_2^4\alpha[/tex]
2) Gamma decay: In this decay process, an unstable nuclei gives excess energy by a process of spontaneous electromagnetic process. This decay process releases [tex]\gamma -radiations[/tex].
[tex]_Z^A\textrm{X}^*\rightarrow _Z^A\textrm{X}+_0^0\gamma[/tex]
3) Beta-plus decay: In this decay process, a neutron gats converted into a proton and an electron. The particle released is [tex]\beta-particle[/tex]
[tex]_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+_0^{-1}\beta[/tex]
4) Beta-minus decay: In this decay process, a proton gets converted into a neutron and an electron neutrino which is known as a positron particle. This is also known as [tex]\beta ^+[/tex]-decay.
[tex]_Z^A\textrm{X}\rightarrow _{Z-1}^A\textrm{Y}+_{+1}^0e[/tex]
Radium-226 nuclei undergoes alpha decay to form Radon-222 nuclei by releasing alpha-particle.
[tex]_{88}^{226}\textrm{Ra}\rightarrow _{86}^{222}\textrm{Rn}+_2^4\alpha[/tex]
Hence, the answer is Option B.
