Chapter 7 Ionic and Metallic Bonding 7.2 Ionic Bonds and 7.1 Ions 7.2 Ionic Bonds and Ionic Compounds 7.3 Bonding in Metals Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Electron Dot Structure Valence Electrons Do Now: Fill in the table. Atom # of Valence Electrons Electron Dot Structure Ion that forms (symbol and charge) Name of ion Li Na Ca O Cl Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Formation of Ionic Compounds Cations + Anions Electrically neutral - Total positive charge = Total negative charge Subscript indicates number of ions - examples: NaCl, CaCl2 https://www.youtube.com/watch?v=xweiQukBM_k https://www.youtube.com/watch?v=zGM-wSKFBpo Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Formation of Ionic Compounds Ionic Bonds - NaCl The sodium atom transfers one valence electron to the chlorine atom. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Formation of Ionic Compounds What ionic compound do you think would form between the following elements? a) Potassium and Oxygen b) Magnesium and Nitrogen Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Oxygen must gain two electrons. Each potassium loses one electron. Sample Problem 7.1 Oxygen must gain two electrons. Each potassium loses one electron. K • • • O + K+ 2– The formula of the compound formed is K2O. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The formula of the compound is Mg3N2. Sample Problem 7.1 b. Each nitrogen needs three electrons to have an octet. Each magnesium atom can lose only two electrons. • • • N 3– + Mg2+ Mg The formula of the compound is Mg3N2. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Magnesium and Fluorine Calcium and Sulfur Potassium and Nitrogen Do Now Write the formula of the ionic compound formed when the following elements combine: Sodium and Chlorine Lithium and Oxygen Magnesium and Fluorine Calcium and Sulfur Potassium and Nitrogen Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Properties of Ionic Compounds Most are crystalline solids at room temperature. High Melting Points Composed of a metal & nonmetal Can conduct electric current when melted or dissolved in water Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Formation of Ionic Compounds Ionic compounds do not exist as discrete units, but as collections of positively and negatively charged ions arranged in repeating patterns. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Formation of Ionic Compounds The structure of an ionic compound is called a crystalline structure. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Formation of Ionic Compounds Formula Units Lowest whole number ratio of ions in an ionic compound. The formula unit for sodium chloride is NaCl. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Properties of Ionic Compounds When sodium chloride is melted, the orderly crystal structure breaks down. To (+) electrode To (–) electrode Inert metal electrodes Flow of electrons Current meter Power source Cl– Na+ This movement of electrons allows electric current to flow between the electrodes through an external wire. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Properties of Ionic Compounds Ionic compounds conduct electric current when dissolved in water. When dissolved, the ions are free to move about in the solution. https://science360.gov/obj/video/25a72599-b1b2-47bd-974c-4957ebc6579f/chemistry-salt-nacl Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

END OF 7.2 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Name the following ionic compounds: SrCl2 Li3N Al2S3 Review for quiz. Do Now Name the following ionic compounds: SrCl2 Li3N Al2S3 Review for quiz. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .