Question

the collapse of the iron core in a massive star results in a ____________. red giant star white dwarf supernova explosion helium flash planetary nebula

Explanation:

When the iron core of a massive star collapses, it leads to a supernova explosion. A red giant star is a stage in the evolution of lower - mass stars before they shed their outer layers. A white dwarf is the remnant of a low - to medium - mass star after it has shed its outer layers. A helium flash occurs in low - mass stars during the red giant phase when helium starts to fuse. A planetary nebula is the outer layers of gas expelled by a low - to medium - mass star. Only a supernova explosion is the result of the collapse of the iron core in a massive star.

Answer:

supernova explosion