2. Ionic Bonds 08/29 & 08/30

3. Catalyst Complete the Chart

4. Objectives I can explain how electrons are transferred in an ionic bond. I can explain that ionic compounds form crystals. I can use the octet rule and the Criss Cross rule to predict how ionic bonds will form.

5. Think Box: Look at your chart above. Do metals form anions or cations? Do nonmetals form anions or cations? Answer: Metals form positive cations. Nonmetals for negative anions.

6. An ionic bond is the electrostatic attraction between oppositely charged ions. eg. Na + and Cl -

7. Ionic compounds form when electrons are transferred from a metal cation to a non-metal anion.

8. An ionic compound is made up of a metal and a non-metal. Sodium + Chlorine Sodium Chloride Lithium + Hydrogen Lithium Hydride Aluminum + Oxygen Aluminum Oxide

9. Ionic compounds form a crystal lattice structure. Sodium + Chlorine Sodium Chloride Silver + Bromine Silver Bromide Magnesium + Tellurium Magnesium Telluride

10. Even though ions have a charge, ionic compounds are neutral overall. Examples Na + + Cl − → NaCl Li + + H − → LiH Ca 2+ + F - → CaF 2 Al 3+ + O 2- → Al 2 O 3 Examples Na + + Cl − → NaCl Li + + H − → LiH Ca 2+ + F - → CaF 2 Al 3+ + O 2- → Al 2 O 3

11. Ionic compound names: list the metal first, then the nonmetal. Change the last syllable of the nonmetal to –ide. If the metal forms more than one cation (transition metals) indicate the ion formed with a roman numeral. Examples Na + + Cl − → NaClSodium Chloride Li + + H − → LiHLithium Hydride Ca 2+ + F - → CaF 2 Calcium Fluoride Al 3+ + O 2- → Al 2 O 3 Aluminum Oxide Ag 2+ + O 2- → AgOSilver (II) Oxide Examples Na + + Cl − → NaClSodium Chloride Li + + H − → LiHLithium Hydride Ca 2+ + F - → CaF 2 Calcium Fluoride Al 3+ + O 2- → Al 2 O 3 Aluminum Oxide Ag 2+ + O 2- → AgOSilver (II) Oxide

12. If ionic compounds are really large collections of ions in a crystal lattice structure, why do we write equations and chemical formulas showing just a few ions? Examples Na + + Cl − → NaCl Li + + H − → LiH Ca 2+ + F - → CaF 2 Al 3+ + O 2- → Al 2 O 3 Examples Na + + Cl − → NaCl Li + + H − → LiH Ca 2+ + F - → CaF 2 Al 3+ + O 2- → Al 2 O 3

13. Compound formulas show the proportion of cations to anions in an ionic compound. The proportion is based on an overall neutral compound. Use the Kris-Cross rule to find the correct proportion.

14. Kris Kross Method! Ca 3 As 2 Ca 2+ As 3-

15. Just kris kross the positive and the negative charges Na 1+ Cl 1- NaCl Pb 4+ O 2- Pb 2 O 4

16. Calcium and Fluorine Step 1: Use the octet rule to write the ions separately. Step 2: Kris-Cross the charge to make subscripts. Ca 2+ F-F- CaF 2 The subscripts shows the proportion of cations to anions. Here, it is 1:2.

17. List the original ions, the chemical formula for the compound formed (with the correct proportions of ions for an overall neutral charge), and the compound name. 1. Sodium and Chlorine Na + Cl - NaCl Sodium Chloride