question_answer

With the help of an example, explain, how the neutron to proton ratio changes during the alpha decay of a nucleus.  

Answer:

                Consider the \[\alpha \] -decay: \[_{92}^{238}U\xrightarrow{_{2}^{4}He}_{90}^{234}Th\] Neutron-proton ratio before \[\alpha \] -decay \[=\frac{238-92}{92}=\frac{146}{92}\] Neutron-proton ratio after \[\alpha \] -decay \[=\frac{234-90}{90}=\frac{144}{90}\] Clearly                  \[\frac{144}{90}>\frac{146}{92}\] Thus the neutron-proton ratio increases during an \[\alpha \]-decay.