Why is zinc conductive?
Because zinc is a metal, that exhibits
And metallic bonding is proposed to be responsible for (i) the malleability (the ability to be beaten into a sheet), and (ii) the ductility (the ability to be drawn into a wire) that ALL metals possess.
Why does metallic bonding confer these properties? Because each metal atom in the metallic lattice contributes 1 or 2 of its valence electrons to the lattice, with the result that the there are free valence electrons holding the metal together electrostatically, such that the positively charged metal nuclei can move with respect to each other WITHOUT disrupting the bonding interaction, and the metal is normally conductive to heat and electricity.