07.1+Ionic+Bonding

=Objectives= Chapter 7 Section 1
 * How do you find the number of valence electrons in an atom of a representative element?
 * Atoms of which element tend to gain electrons? Atoms of which element tend to lose electrons?
 * How are cations formed?
 * How are anions formed?

Chapter 7 Section 2
 * What is the electrical charge of an ionic compound?
 * What are three properties of ionic compounds?

Chapter 7 Section 3
 * How can you model the valence electrons of metal atoms?
 * How are metal atoms arranged?
 * Why are alloys important?

=Outlined Notes=

1. Ions
A. Valence electrons 1. __Valance__ __electrons__ are the electrons in the highest occupied energy level of an element's atoms. 2. To find the number of valence electrons in an atom of a representative element, simply look at its group number 3. __Electron dot Structures__ are diagrams that show valence electrons as dots. B. The Octet Rule 1.In forming compunds, atoms tend to achieve the elctron configuration of a nobel gas (except Helium) has eight electrons in its highest occupied energy level and a general electron configuration of ns2np6. 2. __octet rule__ is atoms react by gaining or losing electrons so as to acquire the stable electron structure of a noble gas, usually eight valence electrons C. Formation of Cations 1. An atom's loss of valence electrons produce a cation, or a positively charged ion. D. Formation of Anions 1, The gain of negatively charged electrons by a neutral atom produces an anion. Ions that are produced when atoms of chlorine and other hologens gain electrons are called "halide ions". 2. __halides__ are ions tht are produced when atoms of chlorine and other halogens gain electrons.

 A. Formation of Ionic Compounds 1**.** __Ionic compounds__**-** compounds composed of cations and anions. 2. Ionic bonds a. __ionic bonds__- electrostatic forces that hold ions together in ionic compounds (ex: NaCl) 3. Formula units a. __chemical formula__- shows the kinds and numbers of atoms in the smallest representative unit of a substance b. formula unit- the lowest whole number ratio of ions is in an ionic compound  B. Properties of Ionic Compounds a. Large attractive forces relate to a very stable substance c. __coordination number__- the number of ions of opposite charge that surround the ion in a crystal.
 * 7.2 Ionic Bond and Ionic Compounds **
 * a. although they are composed of ions, ionic compounds are electrically neutral.
 * 1. Most ionic compounds are crystalline solids at room temperature. 
 * b. Ionic compounds generally have high melting points
 * d. Ionic compounds can conduct an electric current when melted or dissolved in water


 * = key concept

**7.3 Bonding in Metals**
A. Metallic Bonds and Metallic Properties 1. The valence electrons of metal atoms can be modeled as a sea of electrons. -__Metallic bonds__ -- Consist of the attraction of the free-floating valence electrons for the positively charged metal ions. B. Crystalline Structure of Metals 2. Metal atoms are arranged in very compact and orderly patterns. C. Alloys 3. Alloys are important because their properties are often superior to those of their component elements. - __Alloys__ -- mixtures composed of two or more elemtents, at least one of which is a metal ex: Brass is an alloy of copper and zinc -brass rings

=Reference Pages=







=Practice Problems 1. Which of the following has the longest bond? = (A) H-F (B) H-I (C) H-Cl (D) H-Br  2. Which of the following is the shortest bond? (A) H-S (B) H-O (C) H-F (D) H-C  3. Which of the following bonds is the longest? (A) C-C double bond (B) C-C triple bond (C) C-H single bond (D) C-C single bond  4. Which of the following is the strongest bond? (A) Mg-O (B) C-H (C) Na-Na (D) H-H  5. Which of the following is the strongest covalent bond? (A) C-H (B) C-F (C) C-N (D) C-O  6. Which of the following is the weakest ionic bond? (A) Cs-I (B) K-I (C) Li-I (D) Na-I  7. Which of the following has the smallest bond dipole? (A) C-H (B) C-F (C) C-Si (D) C-C  8. Which of the following molecules has a net dipole? (A) NH3 (B) SF6 (C) CCl4 (D) SiH4  9. What is the relationship between bond dipole and bond strength? (A) Bonds with larger dipoles tend to be weaker than those without dipoles. (B) Bonds with larger dipoles tend to be stronger than those without dipoles. (C) There is no relationship. (D) None of the above  10. What is electronegativity? (A) The amount of energy released when an electron is added to an atom (B) The charge on an atom in its preferred oxidation state (C) The power of an atom to attract electrons to itself (D) None of the above

=Assignments= []

=Labs http://www.infoplease.com/chemistry/simlab/ [|http://educ.queensu.ca/%7Escience/main/concept/chem/c07/C07LAAS2.htm]=

__Ionic Bonding Lab []__

=Sample Test= [] [] [] [] [] [] [] [] []
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= = =**Links**=

[] [] http://dl.clackamas.cc.or.us/ch104-06/valence_electrons.htm http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch8/index.php#valence http://www.promotega.org/UGA06004/ionic_bonds.html http://www.visionlearning.com/library/module_viewer.php?mid=55 [] [] [] [] [] [] [] []