Question

Find out the missing particle for the nuclear reaction as shown below:
${}_{92}^{238}U{\to }_{90}^{234}Th+(?)$

• A. $\alpha$
• B. ${}_{-1}{e}^0$
• C. neutron
• D. photon
• E. proton

Answer 1

The correct option is A $\alpha$

The given reaction : ${}_{92}^{238}U{\to }_{90}^{234}Th$ $+$ ${}_Z^{A}X$

In nuclear reactions, the mass number as well as the atomic number is conserved.

$\therefore$ $238=234+A$ $⟹A=4$

Also, $92=90+Z$ $⟹Z=2$

Thus the missing particle is ${}_2^{4}He$ (alpha particle).