There should be heavy elements there...in abundance.
I don't think convection mixing
would be efficient near the core of Jupiter. so sedimentation may haved concentrated a higher ratio of 'heavy elements' [i.e., silicon, calcium, iron, etc..] at the core than in the cloud-layers of Jupiter.
Most scientists agree that's the case.
Ahhh! But the sun, that's a different story.
cheers.
Jacob