Final answer:
The proton-proton chain results in the production of helium, with the intermediate formation of deuterium and helium-3, as well as the emission of positrons, neutrinos, and gamma radiation.
Step-by-step explanation:
The net result of the proton-proton chain, which is the series of nuclear reactions that power stars like the Sun, is the production of helium (He). Throughout the process, four hydrogen nuclei (protons) are ultimately fused to form one helium nucleus. This process occurs in several steps with intermediate products such as the creation of deuterium (a proton and a neutron) and helium-3 (two protons and one neutron). Alongside the production of helium, the reactions also generate positrons, neutrinos, and gamma radiation. Specifically, a deuterium nucleus fuses with a proton to create helium-3 and energy is released in the form of gamma rays. The positrons generated in the first step of the chain react with electrons, resulting in the annihilation of both and more gamma rays. The process is highly energetic, vastly contributing to the luminosity and heat of the Sun.