What is the general upper limit for elements synthesized within the shell ejected by a dying, mid-mass star (Planetary Nebula)?

Answer

Elements up to iron

Planetary nebulae contain elements synthesized during the star's life, typically including elements up to iron, but generally nothing heavier because the star was not massive enough to fuse beyond that point.

What is the general upper limit for elements synthesized within the shell ejected by a dying, mid-mass star (Planetary Nebula)?
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