Metallic Bonding 7.3

Electron Sea Model

The electron sea model proposes that all the metal atoms in a metallic solid contribute their valence electrons to form a “sea” of electrons. This sea of electrons surrounds the metal cations.

Electron Sea Model Diagram

Properties of Metallic Bonds• The electrons can move easily from one atom to the next.

• Because they are free to move, they are often referred to as delocalized electrons.

• A metallic bond is the attraction of a metallic cation for delocalized electrons.

Properties of Metals• Metals have high melting points & boiling points

• Metals are malleable which means they can be hammered into sheets & they are ductile which means they can be drawn into wires

• The delocalized electrons cause heat to be conducted better in metals

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Bonding in Metals> Crystalline Structure of Metals

Metal atoms are arranged in very compact and orderly patterns.

7.3

Alloys

• Alloys are mixtures composed of two or more elements of which one must be a metal.

• Alloys are important because their properties are often superior to those of their component elements.

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Bonding in Metals> Alloys

The most important alloys today are steels. Steels have a wide range of useful properties, such as corrosion resistance, ductility, hardness, and toughness.

7.3

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Bonding in Metals> Alloys

Bicycle frames are often made of titanium alloys that contain aluminum and vanadium.

7.3

Classwork

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