What is the fundamental reason for the chemical energy produced in a chemical process?

If the binding energy per nucleon in $Li^7$ and $He^4$ nuclei are respectively $5.60 \ MeV$ and $7.06 \ MeV$, then the energy of the reaction $Li^7 + p \to 2He^4$ is ......... $MeV$.

An alpha particle $\left({ }^{4} He\right)$ has a mass of $4.00300 \ amu$. $A$ proton has a mass of $1.00783 \ amu$ and a neutron has a mass of $1.00867 \ amu$. The binding energy of an alpha particle estimated from these data is closest to: (in $MeV$)

The energy equivalent of $1.0 \text{ kg}$ of substance is . . . . . . .

Nuclear fission is possible because the binding energy per nucleon ...

The neutron separation energy is defined as the energy required to remove a neutron from the nucleus. Obtain the neutron separation energies of the nuclei $_{20}^{41} Ca$ and $_{13}^{27} Al$ from the following data:
$m(_{20}^{40} Ca) = 39.962591 \; u$
$m(_{20}^{41} Ca) = 40.962278 \; u$
$m(_{13}^{26} Al) = 25.986895 \; u$
$m(_{13}^{27} Al) = 26.981541 \; u$
(Given mass of neutron $m_n = 1.008665 \; u$)