8.1 Forming chemical bonds
formation of positive ions, negative ions, electron dot structure, pseudo-noble gas configurations, cation
formation of negative ions, anion
8.2 Formation and Nature of Ionic Bonds
form the bond, properties of compounds, formulas (determine charge), name ions & ionic compounds
Properties of ionic compounds, electrolyte, lattice energy
8.3 Names and Formulas for Ionic Compounds
metallic bonds, metal alloys, formula unit, monatomic ion, oxidation number, polyatomic ion, oxyanions
8.4 Metallic Bonds and Properties of Metals
Electron sea model, delocalized electrons, metallic bond, alloy, malleable, ductile
The following is an actual summary of this chapter which may be helpful for you:
The bonding in metals is explained by the electron sea model, which proposes that the atoms in a metallic solid contribute their valence electrons to form a “sea” of electrons that surrounds metallic cations. These delocalized electrons
are not held by any specific atom and can move easily throughout the solid. A metallic
bond is the attraction between these electrons and a metallic cation.
Many of the properties of metals can be explained by means of
metallic bonds and delocalized electrons. For example, metals generally
have extremely high boiling points because it is difficult to
pull metal atoms completely away from the group of cations and
attracting electrons. The melting points are considerably lower
because of the mobility of the cations and electrons, which can
move past each other. Metals are also malleable (able to be hammered
into sheets) and ductile (able to be drawn into wire) because
of the mobility of the particles. The delocalized electrons make metals
good conductors of electricity. These electrons also interact with
light, which is why metals tend to be highly lustrous.
A mixture of elements that has metallic properties is called an
alloy. Alloys can be of two basic types. A substitutional alloy is one
in which atoms of the original metal are replaced by other atoms of
similar size. An interstitial alloy is one in which the small holes in a
metallic crystal are filled by other smaller atoms.
Here are a few practice problems to check your understanding of this section:
27. An unknown substance is found to be a good conductor of electricity when melted. Explain whether on this basis alone the substance can be classified as a metal.
28. Suppose the substance in question 27 is allowed to solidify. It is then hammered, and shatters as a result. What property is being tested? Would you classify this material as a metal? Explain your answer.
29. A certain sample of an element is known to be either nickel, sulfur, or iodine. The sample is found to be a good conductor of electricity as a solid. Which element is it likely to be? Why? What other properties would you expect the sample to have?
30. Carbon steel is made by filling the holes in an iron crystal with atoms of carbon. As what type of material is such a mixture classified?
31. Brass is a mixture in which some of the atoms in a crystal of
copper are replaced by zinc atoms, which are of similar size. As
what type of material is such a mixture classified?
If you would like to check your answers to these questions, you can go to Answers to practice problems
Section 8.1 Forming Chemical Bonds
- 12/2/2016 Cornell Notes on Ch 8.1 (one page + of notes in Cornell Style) (5 pts)
Section 8.2 The Formation and Nature of Ionic Bonds
- 12/7/2016 Go to Link on today's HW page for Ionic Bonding Tutorial Label notes 1-27 to match each screen of the tutorial. 1-2 sentences for each screen. (5 pts)
Section 8.3 Names and Formulas for Ionic Compounds
Section 8.4 Metallic Bonds and Properties of Metals