Final answer:
The production of elements in stars depends on their mass and lifecycle stages. Heavier elements than iron only form during supernova explosions, showing that not all stars produce all elements.
Step-by-step explanation:
The statement that 'All elements are produced by all stars' is not completely true because the types of elements that a star can produce depend on its mass and lifecycle. Stars with masses higher than about 8 solar masses can produce elements up to iron through nucleosynthesis in their core. However, elements heavier than iron are synthesized in the supernova explosions that mark the end of a massive star's life.
Furthermore, the very first stars in the universe, composed mostly of hydrogen and helium, started the process of creating heavier elements. As we observe different star generations, we notice that later ones, such as those in open clusters, contain a higher proportion of heavy elements compared to ancient globular clusters. This progressive enrichment shows that not all stars are capable of producing all elements, and it emphasizes how chemical composition evolves over successive generations of stars, with new elements being added by processes like red giant stars' core reactions and supernovae.