What is fission?

Fission refers specifically to the process of splitting a heavy atomic nucleus into two or more smaller nuclei, along with a release of energy in the form of heat and radiation. This process occurs in certain heavy elements, such as uranium-235 or plutonium-239, and is the principle behind nuclear power generation and atomic bombs. When the nucleus splits, it releases a significant amount of energy due to the conversion of some of the mass of the nucleus into energy, as described by Einstein's mass-energy equivalence formula (E=mc^2).

In contrast, the other options involve different nuclear processes or energy transformations. For instance, nuclear fusion (the combining of light nuclei into a heavier nucleus) generates energy in stars but is not the same as fission. The transformation of energy from sunlight pertains to solar energy processes, which are unrelated to nuclear reactions. Therefore, recognizing that fission specifically denotes the splitting process helps in understanding its application and significance in both energy production and nuclear reactions.