Metal cations in a metal solid structure are primarily held together by which force?

The correct answer is the attraction of metal cations to electrons. In metal solids, the structure is characterized by a lattice of positive metal cations surrounded by a 'sea' of delocalized electrons. This model, often referred to as metallic bonding, explains how the cations are held together.

The delocalized electrons are not bound to any specific atom; instead, they move freely throughout the lattice, creating a negative charge that helps maintain electrostatic attraction between the positively charged cations and the negatively charged electrons. This attraction is what provides metals with their distinct properties, such as electrical conductivity and malleability.

The other choices do not accurately describe the primary force holding metal cations in a solid structure. Bonds with nonmetals are not a factor in metallic bonding, and there is no significant repulsion between cations that would stabilize the structure. Shared pairs of electrons are characteristic of covalent bonding, which is not the primary interaction in metals.