T<span>his reaction, known as nuclear fusion, converts hydrogen atoms into helium. The by-product of nuclear fusion in the </span>Sun's<span> core is a massive volume of </span>energy<span> that gets released and radiates outward toward the surface of the </span>Sun<span> and then into the solar system beyond it.</span>
The sun produces energy by nuclear fusion of hydrogen into helium in its core. Since there is a huge amount of hydrogen in the core, these atoms stick together and fuse into a helium atom.
