* Hydrogen (H): This is the fuel for the Sun's fusion reactions.
* Helium (He): This is the primary product of the fusion reactions.
The dominant process within the Sun is called the proton-proton chain reaction. This chain reaction involves several steps:
1. Two protons (hydrogen nuclei) collide and fuse to form deuterium, releasing a positron and a neutrino.
2. A deuterium nucleus collides with a proton to form a helium-3 nucleus, releasing a gamma ray photon.
3. Two helium-3 nuclei collide and fuse to form a helium-4 nucleus, releasing two protons.
Overall: The net reaction is: 4 protons -> helium-4 nucleus + 2 positrons + 2 neutrinos + 2 gamma ray photons
In addition to these primary elements, trace amounts of heavier elements are also present in the Sun, but these are not directly involved in the dominant fusion processes.
