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Learn about metallic bonds and the properties they give to metals. Discover how metal ions form bonds and how the valence electrons can be modeled as a sea of electrons. Explore the crystalline structure of metals and the importance of alloys.
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7.3 Bonding in Metals • You have probably seen decorative fences, railings, or weathervanes made of a metal called wrought iron. In this section, you will learn how metallic properties derive from the way that metal ions form bonds with one another.
7.3 Metallic Bonds and Metallic Properties • Metallic Bonds and Metallic Properties • How can you model the valence electrons of metal atoms?
7.3 Metallic Bonds and Metallic Properties • The valence electrons of metal atoms can be modeled as a sea of electrons. • The valence electrons are mobile and can drift freely from one part of the metal to another. • Metallic bonds consist of the attraction of the free-floating valence electrons for the positively charged metal ions.
7.3 Metallic Bonds and Metallic Properties • Metals are ductile—that is, they can be drawn into wires.
7.3 Metallic Bonds and Metallic Properties • A force can change the shape of a metal. A force can shatter an ionic crystal.
7.3 Crystalline Structure of Metals • Crystalline Structure of Metals • How are metal atoms arranged?
7.3 Crystalline Structure of Metals • These tomatoes have a closed-packed arrangement. Similar arrangements can be found in the crystalline structure of metals.
7.3 Crystalline Structure of Metals • Metal atoms are arranged in very compact and orderly patterns.
7.3 Alloys • Alloys • Why are alloys important?
7.3 Alloys • Alloys are mixtures composed of two or more elements, at least one of which is a metal. • Alloys are important because their properties are often superior to those of their component elements.
7.3 Alloys • Bicycle frames are often made of titanium alloys that contain aluminum and vanadium.
7.3 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 Section Quiz. • 7.3.
7.3 Section Quiz. • 1. The valence electrons of metals can be modeled as • a body-centered cube. • octets of electrons. • a rigid array of electrons. • a sea of electrons.
7.3 Section Quiz. • 2. In most metals, the atoms are • free to move from one part of the metal to another. • arranged in a compact and orderly pattern. • placed at irregular locations. • randomly distributed.
7.3 Section Quiz. • 3. Alloys are important because they • are pure substances. • are the ores from which metals can be refined. • can have properties superior to those of their components. • are produced by the combustion of metals.
