Chapter 17: 17.3 Bonding in Metals

Metallic Bonds and Metallic Properties Metals are made up of closely packed cations. The valence e- around the nucleus of metal atoms are often referred to as a sea of e- They are mobile and can move around freely. Metallic bonds consist of the attraction of the free- moving e- to the positively charged metallic ions. These bonds force the particles together. As a result, they are good conductors of heat and electricity. They are ductile as well as malleable.

Crystalline Structure of Metals Metals that contain only one kind of atom are the simplest of all crystalline structures. They are arranged in a very compact and orderly pattern. Several arrangements are possible. Body-centred, face-centred, and hexagonal close-packed are three examples. Figure 7.14, page 202

Alloys Alloys are mixtures of two or more elements, at least of which one is a metal. Ex. Brass, pewter, sterling silver. Alloys are considered to be superior products compared to their respective elements. Typically, harder and more durable. The most important commercial alloys we deal with is steel.

For the remainder of class… Correct Section 6.2 as a class. Go over questions 14 – 22, p Finish the guided reading for Chapter Seven. Begin the review for your test on Tuesday, Oct. 20 Chapter 5.1, Chapter 6.1, 6.2, Chapter 7.