Final answer:
The statement is false; massive stars do not generate energy by fusing iron in their cores, as iron fusion absorbs energy, leading to a star's collapse and ultimately a supernova, not energy generation.
Step-by-step explanation:
The statement that the most massive stars generate energy at the end of their lives by fusing iron in their cores is false. In the life cycle of massive stars, once the core is primarily iron-nickel metal, no further energy can be generated through fusion, as any fusion involving the iron nucleus actually absorbs energy rather than releasing it. The processes leading up to iron fusion in massive stars involve the fusion of lighter elements into progressively heavier ones, releasing energy and enabling the star to shine. However, with the iron core's formation, the star runs out of fuel for energy generation, and the core begins to collapse under gravity, leading to a supernova explosion, not the generation of energy through iron fusion.