It has long been theorized that hydrogen, helium, and lithium were the only chemical elements in existence during the Big Bang, and that supernova explosions are responsible for transmuting these elements into heavier ones. Researchers are now challenging this and propose an alternative model for the formation of nitrogen, oxygen, and water based on the history of Earth’s atmosphere. They postulate that the 25 elements with atomic numbers smaller than iron were created via an endothermic nuclear transmutation of two nuclei, carbon and oxygen.
