Question

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

• A. $92,326$
• B. $88,230$
• C. $90,234$
• D. $91,234$

Answer 1

The correct option is D $91,234$

$\alpha$:
$\Delta M$ $=4(2n+2p)$
$\Delta Z$ $=2$

$\beta$:
$\Delta M$ $=0$
$\Delta Z=-1$

By mass and charge balance:
$A=238-4=234$
$Z=92-2+1=91$