During the fusion process, how is mass converted into energy?

This is computed using Einstein's well-known equation.

There is sufficient pressure in fusion reactions, such as those occurring in a star's core, for two hydrogen nuclei to combine to form one helium nucleus.

Suppose that four hydrogen nuclei are fused together to form one helium nucleus. Then, how does the Sun maintain its stability in the absence of external energy?

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When light nuclei fuse together to form a heavier nucleus, the resulting nucleus has slightly less mass than the sum of the masses of the original nuclei. This mass difference is converted into energy, releasing an enormous amount of energy in the form of photons. This process is described by Einstein's famous equation, E=mc^2, where E represents energy, m represents mass, and c represents the speed of light.

During the fusion process, mass is converted into energy through the process called nuclear fusion. In nuclear fusion, atomic nuclei combine to form a heavier nucleus, releasing a tremendous amount of energy. This energy is released due to the difference in binding energy between the original nuclei and the resulting nucleus. According to Einstein's famous equation, E=mc^2, mass and energy are interchangeable, where 'E' represents energy, 'm' represents mass, and 'c' represents the speed of light. Therefore, when atomic nuclei fuse, the mass of the resulting nucleus is slightly less than the sum of the masses of the original nuclei, and this difference in mass is converted into energy in accordance with Einstein's equation. This released energy is what powers stars, including our Sun, and is also utilized in nuclear fusion reactions as a potential source of clean and abundant energy on Earth.