Explain why nuclear fusion requires such high energies, but also releases such high energies.

Nuclear fusion requires high activation energy to bring the nuclei close enough to fuse together. The released energy is from the leftover mass. As a result, more energy is released than it is required to merge two nuclei.What is meant by nuclear fusion?Nuclear fusion is a reaction by which two light atomic nuclei combine to form a heavier nucleus while releasing massive amounts of energy. The reaction releases so much energy because the total mass of the resulting single nucleus is less than the mass of the two original, lighter nuclei. Energy that is released comes from the leftover mass.According to Einstein's famous equation E = mc², mass can be converted to energy and vice versa. One of the application of the equation is nuclear fusion.Learn more about Einstein's equation here: https://brainly.com/question/1603546#SPJ4