What element's fusion marks the terminal point in massive stars because fusion of this element consumes energy rather than releasing it?

Answer

Iron

Massive stars fuse progressively heavier elements in shells until the core forms iron. Fusion of iron consumes energy, instantly removing the outward pressure support and leading to catastrophic collapse.

What element's fusion marks the terminal point in massive stars because fusion of this element consumes energy rather than releasing it?
astrophysicscelestial bodystar evolutionstellar massStar lifecycle