KEY2CHEM

Structure of Metallic Solids

The bonding in metallic solids can be described by the electron sea model. Metal cores (composed of metal nuclei and inner electrons) are surrounded by delocalized valence electrons. These valence electrons are not tightly affixed to any single metal core, and the movement of these valence electrons gives metallic solids their unique properties.


Example 1.

Which diagram best depicts a metallic solid?

A. 

B. 

C. 

 

 

Solution 

C. 

 

A metallic solid has metal cores (nuclei plus inner electrons) with delocalized valence electrons, as described by the electron sea model.


Example 2.

What is true about bonding in metallic solids?

 

A. Cations and anions are held rigidly in place.

B. Pairs of metal atoms are held in place by a localized electron pair.

C. Metals are held together by the mutual attraction of metal cations for mobile valence electrons.

 

 

 

Solution

 

C. Metals are held together by the mutual attraction of metal cations for mobile valence electrons.

Unlike ionic bonding, there are no anions present in metals. Unlike covalent bonding, no particular pair of metal atoms is bonded through a localized electron pair.

Example 3.

 

The valence electrons in metallic solids are _________________.

A. localized

B. delocalized

C. nonexistent

 

Solution

 

B. delocalized

The valence electrons in metallic solids are delocalized, meaning that they are loosely attached to metal cores and associate with many metal nuclei.