The Sun generates most of its light during a series of nuclear reactions called the proton-proton chain. The overall process of these nuclear reactions can be summarized as4 1H → 2He + 2ν + 2γ + 2? Where ν is a small neutral particle called a neutrino, and γ is a photon (a particle of light), which is also neutral. The pre-subscripts on the element symbols H (hydrogen) and He (helium) indicate the number of protons in the nucleus of each element. What is the charge of the unknown entity "?"