1. Chapter 15 Ionic Bonding and Compounds

2.  The properties and chemical reactivity of all compounds is based on how they are bonded together.  In this unit we will look at Ionic, Covalent and Metallic bonds  Ionic compounds are compounds formed by atoms giving up or receiving electrons.

3. Ionic compounds (p.422) Fluoride compound Microscopic view of an ionic compound

4. Sodium Chloride

5. Limestone: Calcium carbonate

6. Review electron configuration and Valence Electrons (p.412-414) Na 1s 2 2s 2 2p 6 3s 1 S 1s 2 2s 2 2p 6 3s 2 3p 4 1s 2 2s 2 2p 6 3s 2 3p 4Cl 1s 2 2s 2 2p 6 3s 2 3p 5 Notice that the number of valence electrons (the electrons in the outer most energy levels) correspond with their ‘family/group’ Add this to your periodic tables

7. Electron Dot Diagrams (p. 414)  Structures that show the element and how many valence electrons it has  See Table 15.1  This will be helpful when determining how many elements are required for chemical bonding

8. The Duet and Octet Rule (p. 414-415)  Remember that most atoms (representative elements) want to obtain the electron configurations of a noble gas; they want their outer most energy level filled  This is called the duet (if the atom is closer to helium, such as Lithium) or octet rule (for the rest of the noble gases)  1s 2 for the duet or ns 2 np6 for the octet

9. Electron Configuration for Cations (p. 414-416)  Remember that Cations are atoms that have LOST electrons. They are positively charged  Look at the Lewis Dot Diagrams for Na and Mg  It is easier for them to LOSE their outer most electrons, so the will form cations and obtain the electron configuration of Neon  Their outer most electrons are in the 3s 2 and 3p 6  They have obeyed the ‘octet’ rule

10. Electron Configuration for Anions (p. 417-418)  Remember that Anions are atoms that have GAINED electrons. They are negatively charged.  Look at the Lewis Dot Diagrams for O and F.  It is easier for them to GAIN electrons in their outer most shells, so the will form anions and also obtain the electron configuration of Neon  Their outer most electrons are in the 3s 2 and 3p 6  They have obeyed the ‘octet’ rule

11. Ionic Bonds (p. 419-421)  Ionic bonds are compounds formed between cations and anions  How would you write the formula potassium chloride?  KCl (a ratio of 1:1)  Now go back and write the Lewis Dot Diagrams for each.  Notice that K is needing to give up one electron and Cl is wanted to gain one electron  Hence the ratio of 1:1

12.  Practice writing the following: Calcium Oxide Barium Nitride Cesium Oxide

13. Homework:  p. 418 #1,2,3,4,6; p. 425 #9, 10, 11, 12abc, 13; p. 432 #20, 23, 24, 26, 30, 33, 37  Take your Chemistry book and binder to lab this week