Final answer:
The spectra of old stars show more heavy elements than those of young stars due to stellar nucleosynthesis.
Step-by-step explanation:
True. Because of stellar nucleosynthesis, the spectra of old stars show more heavy elements than those of young stars. Stellar nucleosynthesis is the process by which new chemical elements are created in stars. In stars with higher masses, nuclear reactions involving heavier elements can build up nuclei as heavy as iron. As stars die and eject matter enriched in heavy elements into interstellar space, each succeeding generation of stars contains a larger proportion of heavy elements. This explains why the spectra of old stars, such as those in ancient globular clusters, show a relatively small abundance of heavy elements compared to younger stars.