Question

Consider two arbitrary decay equations and mark the correct alternative(s) given below.
(i) ${}_{92}^{230}U\to n{+}_{92}^{229}U$
(ii) ${}_{92}^{230}U\to p{+}_{91}^{229}Pa$
Given $M\left({}_{92}^{230}U\right)=230.033927uM\left({}_{92}^{229}U\right)=229.03349u$
$m_n=1.008665u$ , $m_p=1.007825$, $1amu=931.5MeV$.

• A. Only decay (i) is possible
• B. Only decay (ii) is possible
• C. Both the decays are possible
• D. Neither of the two decays are possible

Answer 1

The correct option is D Neither of the two decays are possible

For decay (i)
$Q=[230.033927–229.033496–1.008665]\times 931.5=–7.7MeV$
For decay (ii) $Q=[230.033927–299.032089–1.007825]\times 931.5$
$\therefore$ Q is negative for both the decay, so none of the decays are allowed.
$\therefore$ (D)