Advanced Placement (AP) Chemistry Practice Exam

What characteristic is associated with metallic bonding?

1. High electronegativity of participating atoms

2. Shared electron pairs between atom pairs

3. Electron sea that allows for malleability and ductility

4. Formation of rigid lattices

The correct answer is: Electron sea that allows for malleability and ductility

Metallic bonding is characterized by the presence of an "electron sea" model, which describes how metal atoms can lose some of their electrons to form a pool of delocalized electrons. These free electrons are not associated with any particular atom and can move throughout the metal structure. This mobility leads to several important properties of metals, such as malleability (the ability to be hammered or pressed into shapes without breaking) and ductility (the ability to be stretched into wires). The metallic bond's unique structure allows the positive metal ions to slide past one another while maintaining a cohesive force due to the attraction between the positively charged ions and the negatively charged, delocalized electrons. This explained behavior is what gives metals their characteristic properties, including conductivity and flexibility, representing the essence of metallic bonding. In contrast, high electronegativity would typically suggest a strong pull on electrons, more characteristic of covalent or ionic bonding rather than metallic. Shared electron pairs are indicative of covalent bonding, where electrons are localized between specific atoms, rather than the delocalized nature seen in metals. Lastly, while rigid lattices can be seen in ionic compounds or some solid-state structures, metals feature more fluid arrangements due to the electron sea that supports their mal