# Why are the valence electrons free to move across a metallic lattice?

Well, the $\text{valence electrons}$ ARE attracted by $\text{multiple nuclei........}$
In $\text{metallic bonding}$ each metal ATOM is CONCEIVED to donate one or two or more VALENCE ELECTRONS to the bulk metallic structure. These electrons are conceived to be delocalized across the ENTIRE metallic lattice. The result? The bulk metal is (i) thermally conductive; and (ii) electrically conductive.