Which element's fusion ultimately causes the core collapse in a high-mass star because it consumes energy instead of releasing it?

Answer

Iron

High-mass stars fuse elements up to iron; iron fusion consumes energy rather than releasing it, removing the outward pressure source needed to fight gravity, leading to core collapse.

Which element's fusion ultimately causes the core collapse in a high-mass star because it consumes energy instead of releasing it?
evolutionstarmassstage