Question

which is the heaviest element produced in large stars by nuclear fusion near the end of their life cycle

Answer 1

The heaviest element produced in large stars by nuclear fusion near the end of their life cycle is iron (Fe). During the fusion process in a star's core, lighter elements fuse to form heavier elements, with iron being the end point of this process in stellar nucleosynthesis. This is because iron has the lowest binding energy per nucleon, meaning that fusion beyond iron does not release energy and instead consumes energy. As a result, once a star builds up an iron core, it can no longer sustain nuclear fusion to counteract gravitational collapse, leading to a supernova explosion if the star is massive enough.