Final answer:
The fusion of two protons in the p-p chain reaction immediately forms deuterium and gamma rays, releasing a positron and a neutrino for charge conservation.
Step-by-step explanation:
The products formed as an immediate result of the fusion of two protons in the p-p chain reaction is deuterium and gamma rays. During this process, two hydrogen nuclei (protons) combine to form a deuterium nucleus, which contains one proton and one neutron; the conversion of a proton to a neutron results in the release of a positron and a neutrino, to conserve charge. Additionally, energy is emitted in the form of gamma-ray radiation. This is only the first step in a series of reactions that occur in the proton-proton chain, which ultimately leads to the formation of helium-4.