Why don't metals break when pounded into sheets or drawn into wires?
Because metallic bonding is non-localized, and extends throughout the metallic lattice. Metal nuclei can move with respect to other metal nuclei without disrupting the forces of attraction.
We are introduced to the notion of metallic bonding relatively early; i.e. positive ions in a sea of electrons, in which each metal centre donates 1 or 2 (or more) valence electrons to the overall metallic lattice and bonding is non-localized.
This notion of non-localized bonding explains (i) the electrical conductivity of metals (the electrons are free to move if a potential difference is applied); (ii) malleability, the metals may be hammered into a sheet; and (iii) ductility, the metals may be drawn into a wire. Electrons are the interstitial glue that gives rise to these properties.
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