1. Ionic Compounds
Chapter 8

2. Forming Chemical Bonds
Chemical Bond: The force that holds two atoms together.
Valence Electrons
Opposite forces attract
Octet Rule

3. Positive Ions Lose e- becomes cation.
Atoms can lose electrons to become more stable.
Na+1 is more stable than Na.

4. Negative Ions Gain e- to become anions
Gain electrons to gain more stable e- config
Cl-1 is more stable than Cl

5. Formation of Ionic Bond
Ionic Bond: electrostatic force that holds oppositely charged particles together in an ionic compound.
Occurs between metals and nonmetals.
Called ionic compounds.

6. Formation of Ionic Bond
NaCl, 1 to 1 ratio of Na and Cl
Na+1 and Cl-1 combine
Oxidation numbers = 0
MgCl?
CaO

7. Properties of Ionic Compounds
+ and – ions in regular pattern
Forms crystals EX: salt
Crystal lattice forms
Strong bonds between them
Have ↑ melting point and boiling point
If aqueous solution can conduct electricity electrolyte.

8. Properties of Ionic Compounds
Formation of ionic compounds is almost always exothermic.
Lattice energy: amount of energy required to separate ions of an ionic compound.
Smaller ions have more negative lattice energy. EX: LiCl more negative NaCl
Larger charges have larger lattice energy. EX: MgO more negative MgCl

9. Formulas for Ionic Compounds
Formula Unit: Simples ratio of ions in ionic compound
Know your oxidation states for monatomic metals and nonmetals
Also know your oxidation states for polyatomic metals and nonmetals
Group
Oxidation number 1 1+ 2 2+ 15 3- 16 2- 17

10. Oxidation Numbers Transition metals have multiple oxidation numbers.
Oxidation number: # of e- transferred from an element to form an ion.

11. Naming Ionic Compounds
Cation always named first.
Cation name does not change. (Na1+, sodium) Ex: NaCl = sodium chloride
Anion named by taking root and adding –ide. (O2-, oxide) Ex: CaO = Calcium Oxide

12. Naming Ionic Compounds
Transition Metals with multiple oxidations must include their oxidation state in the name of the compound. [Fe2+, Iron (II)] EX: FeO = Iron (II) oxide EX: Fe2O3 = Iron (III) oxide
If an atom contains a polyatomic ion simply name that ion. Know oxidation states of polyatomic ions EX: NaOH = Sodium Hydroxide EX: AgNO3 = Silver Nitrite

13. Naming Ionic Compounds
Older method of naming transition metals
Root word followed by –ous, for lower oxidation, or –ic, higher oxidation
EX: Cuprous ion = Copper (I)
EX: Cupric ion = Copper (II)
EX: Ferrous ion = Iron (II)
EX: Ferric ion = Iron (III)

14. Naming Ionic Compounds
Yes No

15. Metallic Bonds and Properties of Metals
Metals do not bond ironically
Form electron sea
Electrons are not held by 1 atom
Delocalized e-, free to move
Metallic bond: attraction of metallic cation for delocalized e-.

16. Metallic Properties Very different melting points. Hg -38 C, W 3422 C.
Ductile and malleable.
Delocalized e- cause metals to be good conductors.
Mobile e- interact with light releasing photons causing luster.

17. Metal Alloys
Alloy: mixture of elements that have metallic properties. EX: steel, Brass
Substantial Alloy: atoms of original metallic solid replaced by other metal atoms of similar size
Interstitial Alloy: small holes in a metallic crystal are filled with smaller atoms