In the disintegration series the $_{92}^{238}U\xrightarrow{\alpha }X\xrightarrow{{\beta  - }}_Z^AY$ values of $Z$ and $A$ respectively will be

Actinium $231$, ${}^{231}A{c_{89}}$, emit in succession two $\beta  - $particles, four alphas, one $\beta  $ and one alpha plus several $\gamma $ rays. What is the resultant isotope

In the given reaction $_z{X^A}{ \to _{z + 1}}{Y^A}{ \to _{z - 1}}{K^{A - 4}}{ \to _{z - 1}}{K^{A - 4}}$ Radioactive radiations are emitted in the sequence

Some radioactive nucleus may emit

The isotope ${ }_5^{12} \mathrm{~B}$ having a mass $12.014 \mathrm{u}$ undergoes $\beta$-decay to ${ }_6^{12} \mathrm{C} .{ }_6^{12 .}$ has an excited state of the nucleus $\left({ }_6^{12} \mathrm{C}^*\right)$ at $4.041 \mathrm{MeV}$ above its ground state. If ${ }_5^{12} \mathrm{~F}$ decays to ${ }_6^{12} \mathrm{C}^*$, the maximum kinetic energy of the $\beta$-particle in units of $\mathrm{MeV}$ is ( $1 \mathrm{u}=931.5 \mathrm{MeV} / c^2$, where $c$ is the speed of light in vacuum).

The nucleus $_{48}^{115}Cd$ after two successive ${\beta ^ - }$ decays will give