Final answer:
The metallic bonding structure, with its sea of delocalized electrons, explains why metals conduct electricity and heat efficiently and possess other properties like malleability, ductility, high melting points, and high density.
Step-by-step explanation:
We can infer about the structure of metals due to their ability to conduct electricity in both solid and molten forms that they have a metallic bonding structure. This metallic bonding is characterized by a sea of delocalized electrons surrounding a lattice of positive ions. Because these electrons are free to move, they can carry electrical current through the structure. This explains why metals are good conductors of heat and electricity.
The presence of delocalized electrons also contributes to other metallic properties such as malleability and ductility. Metals can be hammered into sheets or drawn into wires without breaking because the metallic bonds are not directional and can maintain their cohesion even when metal atoms are forced to move past each other. Additionally, the high melting points and density of metals can be attributed to the strong attractions between the densely packed positive ions and the sea of electrons.