What is the nucleus and all electrons in an atom except the valence electrons?

Question

What is the nucleus and all electrons in an atom except the valence electrons?

Answer 1

All of that would be the "non-chemically reactive" part of the atom.

Consider this:  Bring two apples closer and closer together, until they touch.  It's the outsides of the apples -- the skin -- that touch, not the cores of the apples, not everything below the skins.

The skin of the apple are the valence electrons.  Those are the ones that will be involved in a chemical reaction.  The nucleus and the inert gas core of electrons, plus any other electrons which are not valence electrons will not be involved in a chemical reaction.

Therefore, they are the "non-chemically reactive" parts of the atom.