Which of the following is the best description of the free flowing electrons and metallic bonding? So here a core electrons that can move freely between metal ions. Remember we said it's valence electrons, the electrons that are found on the outer shell in terms of the element or ion. So this doesn't make sense. So A is out.
B would also be out because again it's including core electrons, valence electrons that can move freely between metal ions. That's what we showed in the picture. Those valence electrons are not confined to each one of their those positive ions, they can move around between them. So C is a good description.
D valence electrons that are bond to metal ions, they're not bound, they can freely move around. And then E again, core electrons are bond to the metal ions, yes, but metallic bonding has to do more with the free flowing of prevalence electrons between positive ions. So C is the best description of metallic bonding.