Question

What occurs to a massive stellar core when it begins fusing iron into heavier elements. Make sure to discuss energy released or absorbed by the reactions.

Answer 1

When a star is fusing iron in its core, it’s still giving off insane amounts of energy. The helium, hydrogen, carbon, oxygen, and silicon are still there in the star in different shells. Hydrogen is at the surface, still fusing to helium; a little further down, helium fusing to carbon and oxygen; further down we have silicon until the core, where silicon fuses to iron. This is why the star still exists and doesn’t spontaneously explode the moment the first iron atom pops into existence.

At this point, the energy process is just no longer exothermic but endothermic. Iron cannot be fused into anything heavier because of the insane amounts of energy and force required to fuse iron atoms. The atomic structure of iron is very stable, more so than most other elements. I’m not saying all other elements are radioactive or unstable, just that iron is slightly more stable than the previous elements.

Stars this massive can turn into several things; it depends on how heavy it is. They can explode into supernova, collapse into various types of neutron stars, or even form a black hole. The iron in the star’s core isn’t the reason why the star went supernova, its overall mass made it explode. But, the iron in its core caused it to die.