Slide 1 of 25 © Copyright Pearson Prentice Hall Ionic Bonds and Ionic Compounds > Formation of Ionic Compounds B. Ionic Compounds: composed of cations and anions held together by electrostatic forces called ionic bonds. 1. Are electrically neutral. a. Total positive charge is equal to the total negative charge. 7.2

Slide 2 of 25 © Copyright Pearson Prentice Hall Ionic Bonds and Ionic Compounds > Formation of Ionic Compounds 2. chemical formula: shows kinds and numbers of atoms in the smallest representative unit of a substance. a. formula unit: lowest whole-number ratio of ions in an ionic compound. i. NaCl : sodium chloride. 7.2

Slide 3 of 25 © Copyright Pearson Prentice Hall Ionic Bonds and Ionic Compounds > Use of dot diagrams to predict formula 3. Electron Dot Structure: can be used to determine the chemical formula of an ionic compound. a. Draw the dot structure for each ion b. Atoms with less than 4 valence electrons (metals) will give electrons to become cations and atoms with more than 4 valence electrons (non-metals) will receive electrons to become anions. c. Determine how many of each ion is needed so the total number of electrons received equals the total number of electrons given. 7.2

© Copyright Pearson Prentice Hall Slide 4 of 25 Conceptual Problem 7.2

© Copyright Pearson Prentice Hall Slide 5 of 25 Conceptual Problem 7.2

© Copyright Pearson Prentice Hall Slide 6 of 25 Practice Problems Problem Solving 7.12 Solve Problem 12 with the help of an interactive guided tutorial. Guided Practice (now you do it)

© Copyright Pearson Prentice Hall Ionic Bonds and Ionic Compounds > Slide 7 of 25 Properties of Ionic Compounds What are three properties of ionic compounds? 7.2

Slide 8 of 25 © Copyright Pearson Prentice Hall Ionic Bonds and Ionic Compounds > Properties of Ionic Compounds Properties of Ionic Compounds: a. Most are crystalline solids at room temperature. b. Generally have high melting points. c. Produce specifically shaped crystals. d. Coordination Number: # ions of __ opposite charge that surround the __ ion in a crystal. i. NaCl: coordination # of 6.

Slide 9 of 25 © Copyright Pearson Prentice Hall Ionic Bonds and Ionic Compounds > Properties of Ionic Compounds 7.2 e. Can conduct an electric current when melted or if dissolved in water.

Slide 10 of 25 © Copyright Pearson Prentice Hall Ionic Bonds and Ionic Compounds > Properties of Ionic Compounds 7.2

© Copyright Pearson Prentice Hall Slide 11 of 25 Ionic Bonds and Ionic Compounds > Properties of Ionic Compounds Simulation 5 Simulate the formation of ionic compounds at the atomic level.

© Copyright Pearson Prentice Hall Slide 12 of Which chemical formula is incorrect? a.KF 2 b.CaS c.MgO d.NaBr 7.2 Section Quiz.

© Copyright Pearson Prentice Hall Slide 13 of Ionic compounds can conduct an electric current a.only when melted. b.when melted or dissolved in water. c.only when dissolved in water. d.when solid or melted. 7.2 Section Quiz.

© Copyright Pearson Prentice Hall Slide 14 of At room temperature, most ionic compounds are a.crystalline solids. b.liquids. c.gases. d.soft, low melting-point solids. 7.2 Section Quiz.

© Copyright Pearson Prentice Hall Slide 15 of 25 Formation of Ionic Compounds Animation 8 Take an atomic-level look at the formation of KCl. GOTO: Unit 7, Section 2, Slide 7 Simulation of the formation of ionic compounds at the atomic level. GOTO: Unit 7, Section 2, Slide 18