2. Chp.12/Activity #3 Chemical Names & Formulas (page 785) Be ready to show your WDYT HW Learning targets Predict charges of ions of some elements Determine formulas of ionic compounds Write the name of ionic compounds

3. Ions and Ionic Compounds Ions form because atoms tend to want to form octets in their valence shell. E.g. K tends to lose an electron to become K + E.g. Oxygen tends to gain 2 electrons to become O -2 When two such atoms are near, the transfer of electrons happen. E.g. Na and Cl will transfer electrons to become Na + and Cl -

4. Unlike charges attract, so the two ions are attracted very strongly to each other. This is called an ionic bond and the atoms involved form an ionic compound. E.g. Na + and Cl - bond to form NaCl. The charges will always balance out to Neutral (Stable). E.g. Need 2 Na + ions for 1 O -2 to get Na 2 O.

5. What kind of ions (charge) would these atoms form? 1.Oxygen 2.Fluorine 3.Chlorine 4.Lithium 5.Beryllium 6.Ruthenium * Note that transition metal ions are hard to predict. Use the Oxidation Numbers in the periodic table! O -2 F -1 Cl -1 Li +1 Be +2 Ru +2 Ru +3, Ru +4, Ru +6, Ru +8

6. Naming Ionic Compounds (Nomenclature) The Cation(+) always comes before the Anion(-). The Cation is written by its name. E.g. NaCl - Sodium ______ The Anion is written by changing its name to an –ide ending E.g. NaCl - Sodium Chloride

7. Can you name these compounds? 1.BaCl 2 2.CaO 3.MnO 4.FeO 5.Fe 2 O 3 But 4 and 5 have the same name! Barium Chloride Calcium Oxide Manganese Oxide Iron Oxide

8. Transition metals have several oxidation states (Oxidation number). They can have many different charges So we also write the oxidation number for transition metals like this. E.g. FeO – Iron (II) Oxide E.g. Fe 2 O 3 – Iron (III) Oxide Remember the total charge will always balance out!

9. Can you name these transition metal compounds? 1.FeCl 2 2.PbBr 4 3.Ni 2 O 3 4.AgBr 5.Mn 2 O 3 Good job! Iron (II) Chloride Lead (IV) Bromide Nickle (III) Oxide Silver Bromide Manganese (III) Oxide