Editing Proton–proton chain (section)

===The {{nowrap|p–p II}} branch===
[[File:Proton-Proton II chain reaction.svg|thumb|Proton–proton II chain]]
{{See also|Lithium burning}}
<!-- Autogenerated using Phykiformulae 0.11 by [[User:SkyLined]]
He-3 + He-4 → Be-7 + y
Be-7 + e- → Li-7 + ve (0.861 MeV / 0.383 MeV)
Li-7 + H → 2He
-->:{| border="0"
|- style="height:2em;"
|{{nuclide|link=no|helium|3}}&nbsp;||+&nbsp;||{{nuclide|link=no|helium|4}}&nbsp;||→&nbsp;||{{nuclide|link=yes|beryllium|7}}||+&nbsp;||{{math|{{SubatomicParticle|link=no|Gamma}}}}&nbsp;||+&nbsp;||{{val|1.59|u=MeV}}
|- style="height:2em;"
|{{nuclide|link=no|beryllium|7}}&nbsp;||+&nbsp;||{{SubatomicParticle|link=no|Electron}}&nbsp;||→&nbsp;||{{nuclide|link=yes|lithium|7}}||+&nbsp;||{{math|{{SubatomicParticle|link=no|Electron Neutrino}}}}&nbsp;||+&nbsp;||{{val|0.861|u=MeV}}&nbsp;||/&nbsp;||{{val|0.383|u=MeV}}
|- style="height:2em;"
|{{nuclide|link=no|lithium|7}}&nbsp;||+&nbsp;||{{nuclide|link=no|hydrogen|1}}&nbsp;||→&nbsp;||2 {{nuclide|link=no|helium|4}}&nbsp;||&nbsp;||&nbsp;||+&nbsp;||{{val|17.35|u=MeV}}
|}

The {{nowrap|p–p II}} branch is dominant at temperatures of 18 to {{val|25|u=MK}}.<ref name=":1" />

Note that the energies in the second reaction above are the energies of the neutrinos that are produced by the reaction. 90 percent of the neutrinos produced in the reaction of {{SimpleNuclide|Beryllium|7}} to {{SimpleNuclide|Lithium|7}} carry an energy of {{val|0.861|u=MeV}}, while the remaining 10 percent carry {{val|0.383|u=MeV}}. The difference is whether the lithium-7 produced is in the ground state or an excited ([[metastable]]) state, respectively. The total energy released going from {{chem|7|Be}} to stable {{chem|7|Li}} is about 0.862&nbsp;MeV, almost all of which is lost to the neutrino if the decay goes directly to the stable lithium.