Transcript: The energy source of the Sun is the conversion by fusion of hydrogen into helium in a three step process called the proton-proton chain. In the first step protons fuse to form deuterium, a nucleus with a proton and a neutron. The release products are a positron, the antiparticle of the electron, and a neutrino, a tiny nearly massless particle. In the second step of the process deuterium has another proton added to form tritium, two protons and a neutron bound together with the release of gamma rays or radiant energy. In the third step of the process two tritium nuclei combine to form a helium nucleus, two protons and two neutrons, with two free protons left over to participate in fusion products further. At each of the three steps in the process energy is released, and the result of all this energy release is the power from the Sun.