SQA National 5 Chemistry Practice Exam

The primary feature of a metallic lattice structure is the presence of delocalized electrons, which play a crucial role in defining the properties of metals. In a metallic lattice, metal atoms contribute their outermost electrons to a "sea" of delocalized electrons that are free to move throughout the structure. This sharing of electrons allows for electrical conductivity, as these electrons can easily flow when an electric field is applied.

Additionally, the arrangement of positive metal ions surrounded by this sea of delocalized electrons results in strong electrostatic attractions, helping to maintain the structural integrity of the metallic lattice. This feature explains why metals can conduct electricity and heat effectively.

In contrast, weak intermolecular forces, while significant in other types of bonding, do not characterize metallic bonding as they pertain primarily to molecular compounds. Likewise, while metallic lattices may exhibit a crystalline structure, the defining characteristic of their behavior, particularly in terms of conductivity, is the mobility of the delocalized electrons.