Physics - Modern Physics Question with Solution | TestHub

The mass defect $\Delta m$ for the given nuclear reaction is:

$\Delta m=m{(}^{238}\text{U})-[m{(}^{234}\text{Th})+m{(}^4\text{He})]$

$\Delta m=238.050-(234.043+4.003)$

$\Delta m=238.050-238.046=0.004\text{ u}$

The $Q$ value of the reaction is given by:

$Q=\Delta m\times 931.5\text{ MeV}$

$Q=0.004\times 931.5\text{ MeV}$

$Q=3.726\text{ MeV}$

Converting to keV:

$Q=3.726\times 10^3\text{ keV}=3726\text{ keV}$

Answer: $3726$