The reaction $_5B^8 \to _4Be^8 + _1e^0$ is due to

During a $\beta$-decay,the mass of the atomic nucleus

The radiations having high penetrating power and not affected by electrical and magnetic field are

Which of the following statements is not true for radioactive decay?

What kind of radioactive decay does not lead to the formation of a daughter nucleus that is an isobar of the parent nucleus?

In the decay sequence:
$^{238}_{92}U$ $\xrightarrow{- x_1} ^{234}_{90}Th$ $\xrightarrow{- x_2} ^{234}_{91}Pa$ $\xrightarrow{- x_3} ^{234}_{92}Z$ $\xrightarrow{- x_4} ^{230}_{90}Th$
$x_1, x_2, x_3$ and $x_4$ are particles/radiation emitted by the respective isotopes. The correct option$(s)$ is/are-
$(1)$ $Z$ is an isotope of uranium
$(2)$ $x_2$ is $\beta^{-}$
$(3)$ $x_1$ will deflect towards negatively charged plate
$(4)$ $x_3$ is $\gamma$-ray