Find the binding energy of ${}_{26}{}^{56}Fe$ Atomic mass  of ${}^{56}Fe$ is $55.9349 u$ and that of ${}^{1}H$ is $1.00783 u.$ Mass of neutron $=1.00867 u$

The number of protons in ${}_{26}{}^{56}Fe$$=26$ and the number of neutrons is $\left(A-Z\right)=56-26=30.$
The binding energy of ${}_{26}{}^{56}Fe$ is 

$$\begin{gathered} BE=\left(26\times 1.00783u+30\times 1.00867u-55.9349u\right)c^2 \\ BE=\left(0.52878\right)c^2 \\ BE=\left(0.52878u\right)\left(931 MeV/u\right)=492 MeV \end{gathered}$$