Answer
$1559MeV$
Work Step by Step
First, we find the mass of the protons and neutrons as:
$m_f=79(1.007825u)+118(1.008665u)=198.640645u$
Now, $\Delta m=m_f-m_i$
$\Delta m=198.640645u-196.96654u=1.6741u$
Now we can find the required energy:
$E=\Delta mc^2$
We plug in the known values to obtain:
$E=1.67411u(\frac{931.5MeV/c^2}{1u})c^2$
$E=1559MeV$
