Which description best characterizes ionic compounds?

Which description best characterizes ionic compounds?

• A. Molecule of alternating metals
• B. Lattice of cations and anions
• C. Covalent network of atoms
• D. Delocalized electron cloud in a metal

Answer: (B)

Ionic compounds are defined by a crystal lattice of oppositely charged ions held together by strong electrostatic forces. This arrangement arises when electrons are transferred from a metal to a nonmetal, forming cations and anions that attract in all directions to create a three-dimensional lattice. That extended lattice, not discrete molecules, explains many properties: high melting points and solids at room temperature, and the ability to conduct electricity only when molten or dissolved (where ions can move). The other descriptions don’t fit ionic solids: a discrete molecule of alternating metals would imply molecules rather than an extended lattice; a covalent network involves shared electrons in a fixed network; and a delocalized electron cloud in a metal reflects metallic bonding, not ionic bonding.

Ionic compounds are defined by a crystal lattice of oppositely charged ions held together by strong electrostatic forces. This arrangement arises when electrons are transferred from a metal to a nonmetal, forming cations and anions that attract in all directions to create a three-dimensional lattice. That extended lattice, not discrete molecules, explains many properties: high melting points and solids at room temperature, and the ability to conduct electricity only when molten or dissolved (where ions can move). The other descriptions don’t fit ionic solids: a discrete molecule of alternating metals would imply molecules rather than an extended lattice; a covalent network involves shared electrons in a fixed network; and a delocalized electron cloud in a metal reflects metallic bonding, not ionic bonding.