1. Chapter 7 Ionic & Metallic Bonding Anything in black letters = write it in your notes (‘knowts’)

2. Valence Electrons & Ion Formation valence electrons electron dot (Lewis) structures cations & anions octet rule Ionic & Metallic Bonding ionic compounds (properties) formula units alloys Chapter 6 Objectives

3. variable

4. Electron Dot Diagrams – valence electrons as dots around chemical symbol These are also known as Lewis Symbols

5. 3 Main Rules for Lewis Symbols 2. Fill all 4 sides before pairing. C ● 1. No more than 2 dots on each side. 3. No more than 8 dots total. ● C C ● ● ● ● C ● ● ● ● ● ● ● ● ● ● wrong Correct!

6. Na Mg AlSi P S Cl Ar Draw Lewis Symbols for these elements 1. Fill all 4 sides before pairing. 2. No more than 2 dots on each side. 3. No more than 8 dots total.

7. Metal atoms lose their valence electrons easily. Nonmetal atoms gain electrons to fill their valence to 8. REMEMBER!! If an atom gains an electron, it becomes a -1 ion If an atom loses an electron, it becomes a +1 ion Ca + ion = positive ion Anion = negative ion

8. Normal Ion Charges

9. Octet Rule – Atoms will gain or lose electrons to have 8 valence electrons.

10. Ionic bonds are formed by electron transfer between a metal & a nonmetal)

11. Ionic compounds consist of cations and anions arranged in repeating patterns; NOT as discrete units like molecules A formula unit is the lowest ratio of ions in an ionic compound.

12. Properties of Ionic Compounds High melting points Crystalline solids at room temperature Conduct electric current when molten or dissolved in water.

13. PRACTICE: #1-9 (p. 199) & #10-19 p. 203, 207)

14. The valence electrons in metals are loosely held and are free to move. The properties of metals can be explained by the ‘sea of electrons’ model. 7.3 – Bonding in Metals

15. Alloy – mixture of metals. Steel – Stainless Steel – Bronze – Solder – Brass – Sterling Silver – Amalgam – Nichrome – Alloy – mixture of metals. Steel – Fe & C Stainless Steel – steel w/ Cr, Ni, or Mn Bronze – Cu & Sn Solder – Sn & Pb Brass – Cu & Zn Sterling Silver – Ag & usually Cu Amalgam – Hg w/ other metals (Ag, Sn, Cu) Nichrome – Ni & Cr

16. Chapter 7 ASSIGNMENTChapter 7 Chapter 7 #27-44 (p. 214)