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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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Slide 10 of 19
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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.
Slide 14 of 19
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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
Slide 13 of 19
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Bonding in Metals> Alloys
Bicycle frames are often made of titanium alloys that contain aluminum and vanadium.
7.3
Classwork
Page 285Problems 1-15