Which reaction is not part of the proton-proton cycle?

How much energy is released by the fusion of four hydrogen atoms to form a helium nucleus (in $MeV$)?

What is nuclear fission and nuclear fusion?

In the nuclear fusion reaction ${ }_1 H^2+{ }_1 H^3 \rightarrow{ }_2 He^4+n$, if the repulsive potential energy between the two nuclei is $2.07 \times 10^{-14} \,J$, then the temperature at which the gases must be heated to initiate the reaction is (Boltzmann constant $k = 1.38 \times 10^{-23} \,JK^{-1}$).

$A$ nucleus with mass number $240$ breaks into two fragments each of mass number $120$. The binding energy per nucleon of the unfragmented nucleus is $7.6 \, MeV$,while that of the fragments is $8.5 \, MeV$. The total gain in the binding energy in the process is (in $MeV$):

$U^{235}$ nuclear reactor generates energy at a rate of $3.70 \times 10^7 \text{ J/s}$. Each fission liberates $185 \text{ MeV}$ of useful energy. If the reactor has to operate for $144 \times 10^4 \text{ s}$, then the mass of the fuel needed is (Assume Avogadro's number $= 6 \times 10^{23} \text{ mol}^{-1}$, $1 \text{ eV} = 1.6 \times 10^{-19} \text{ J}$) (in $\text{ kg}$)