What element's formation causes fusion to stop abruptly in high-mass stars because fusing it consumes energy?

Answer

Iron

Iron acts as the crucial turning point in massive stars; unlike lighter elements, fusing iron consumes energy rather than releasing it. When the iron core forms, fusion ceases instantly, causing the outward pressure supporting the star to vanish.

What element's formation causes fusion to stop abruptly in high-mass stars because fusing it consumes energy?
astronomystellarstarstellar periodperiod