Question

In the decay sequence, $\ce{^{238}_{92}U->[-x_1] ^{234}_{90}Th->[-x_2] ^{234}_{91}Pa ->[-x_3]^{234}Z->[^{-x_4}] ^{230}_{90}Th}$
$x_1,x_2, x_3$ and $x_4$ are particles/radiation emitted by the respective isotopes. The correct option(s) is(are)

• A. $x_1$ will deflect towards negatively charged plate
• B. $x_{2}$ is $\beta^{-}$
• C. $x_{3}$ is$\gamma$-ray
• D. $Z$ is an isotope of uranium

Answer 1

Answer: (A), (B), (D)

$_{92}U^{238} \to _{90}Th^{234} + _{2}He^{4}$
$_{90}Th^{234} \to _{91}Pa^{234} + -1^{e^0}$
$_{91}Pa^{234} \to _{92}Z^{234} + -1^{e^0}$
$_{92}Z^{234} \to _{90}Th^{230} + _{2}He^{4}$
$\therefore \,x_{1} = \alpha ; x_{2} = x_{3} = _{-1}\beta^{0} ; x_{4} = \alpha$
Z has atomic number 92.