Chapter 32 - Nuclear Physics and Nuclear Radiation - Problems and Conceptual Exercises - Page 1153: 42

$39.25MeV$

First we find the mass of the protons and neutrons as: $m_f=3(1.007825u)+4(1.008665u)=7.058135u$ Now, $\Delta m=m_f-m_i$ $\Delta m=7.058135u-7.016003u=0.042132u$ Now we can find the required energy: $E=\Delta mc^2$ We plug in the known values to obtain: $E=0.042132u(\frac{931.5MeV/c^2}{1u})c^2$ $E=39.25MeV$