Question

Although more sophisticated models for the structure of metallic solid are available, including the band model, most properties of metals can be explained by a relatively simple model, based on the fact that metals have low ionization energies, resulting in their having loosely held valence electrons, which can move freely among the metal cation.

The diagram below illustrates this. The positive circles represent the metal kernels (nucleus plus core electrons) while the small circles with minus signs represent the "sea" of valence electrons.
This model is used to explain most, if not all, of the physical properties of metals.

Of the properties listed below, which one cannot be explained by this model?

• A. Metals are good conductors of electric currents; they are good for electric wiring.
• B. Metals are good thermal conductors; they transfer heat easily.
• C. Metals can form alloys, by mixing with other metals or with nonmetals, such as carbon.
• D. Metals are malleable and ductile. They can be made into wires and bent into a wide variety of shapes.

Answer 1

The correct option is C Metals can form alloys, by mixing with other metals or with nonmetals, such as carbon.

(A) Metals are good conductors as delocalized electrons act as charge carriers.

(B) Metal are good conductors of heat because the delocalized electrons can carry kinetic energy throughout the lattice.

(C) Metal can form alloys only with metals according to the electron sea model via metallic bonding.

(D) Metals are ductile and malleable because local bonds can be easily broken and reformed due to the presence of a sea of electrons.

Answer: (C) Metals can form alloys, by mixing with other metals or with non-metals, such as carbon.