Which type of reaction does this diagram represent? A central starburst has superscript 2 upper H and superscript 3 upper H pointing to it, and n plus energy and superscript 4 upper H e plus energy pointing away from it. nuclear fission because an atom is splitting into two fragments nuclear fusion because the products that are produced are radioactive nuclear fission because a large amount of energy is being released nuclear fusion because atomic nuclei combine to form a heavier nucleus