Why are younger stars have more heavier elements than older stars?

Question

Why are younger stars have more heavier elements than older stars?

Answer 1

Because older stars were formed when there was less heavy elements in interstellar space.  The older stars, in fact, add to the heavy elements in interstellar nebulas when they go supernova, so that younger stars, which form out of them, contain more, generally.

The very first stars to form in the galaxy had nothing but hydrogen and helium in the interstellar medium to form out of.  As the first stars lived their lives (metephorically) and went supernova, they added heavy elements to the rest of space, which younger stars were able to incorporate.

I couldn't decide which paragraph explains it best.

Answer 2

Older stars have burnt most of their elements off. Younger stars are still forming and still has alot of things in them.

Answer 3

Over the star's life, it fuses the lighter elements together into heavier elements. Hydrogen fuses into Helium. Helium and Hydrogen fuse into Lithium. Helium fuses into Berylium. By the time a star is producing Lithium and Berylium in any real volume, it is in its death throes.

During the collapse or explosion of a star, many, much, much heavier elements are forged.