1.Combination of atoms to form a compound (with different properties) 2. Determined by electrons in atoms 3. Why bond?  To increase stability  To decrease energy  To fill valence!! 4. A balanced combination of positive and negative ions. 5. Simplest whole number ratio

 Chemical compounds form so that each element has a full octet of electrons in its highest energy level.  This can happen through gaining, losing, or sharing electrons.

 Review Unit 5 Tests  Redo policy  Before Thanksgiving Break?  Review Ionic Compounds  Properties  Continue Puzzle Piece activity  Let’s Clarify the directions  HW: Finish analysis questions for Activity

 Ionic Bond  The chemical bond resulting from electrostatic attraction between positive and negative ions.  Metals tend to lose electrons and form cations.  Nonmetals tend to gain electrons and form anions

 Solid state is a crystalline structure  Hard, brittle solids  High melting point  NaCl is 801 o C  Do not conduct electricity as solids  Do conduct as liquids and solutions  Not discreet molecules, instead called formula units

 Identify charges of both the cation and the anion.  Collect puzzle pieces that correspond to the ions.  Adding more of only those charges, continue adding pieces until you have a complete and stable compound. Puzzle Method

 Sodium Oxide  Calcium Sulfide  Aluminum Chloride

 Each pair needs new puzzle pieces  The goal of fitting the pieces together is to make a complete rectangle or square.  Cations can only bond with anions!!  Your job is to make 20 combinations  Do Not try the Naming Yet!!!

 Finish Formula Writing Lab  Homework for tomorrow  Go Over Unit 5 Test  Collect Formula Writing Lab (3 and 8)  1 per group  Notes on writing and naming Ionic Compounds

 Meet with your lab partners  Compare answers to analysis questions, and your conclusions.  Determine which of the two labs you will turn in.  Both partners names should be on the lab.

 Get into your white board groups  One marker per group

 Write the correct formula for the following cation and anion pairs: 1. Na + and Cl - 2. Mg +2 and F - 3. C -4 and H + 4. Ag +3 and O Ag +3 and N -3 Bonus Question: Is there a pattern you notice between the charges on the ions and the subscripts in the formulas?

 Identify charges of both the cation and the anion.  Switch the charge value to be the opposite ion’s newest subscript.  Repeat for the other ion. Example: Ag +3 O -2 Ag 2 O 3

 Ag +3 and N -3  Do the criss-cross method  If the subscripts can be reduced…reduce them!

 Cation is always named first  Cation  take the name of the element  Transition metals  use the formula to find the charge (Roman numeral = charge)  Anion  Monatomic (only one element)  end in –ide

 CaF 2  calcium fluoride  Li 2 S  Lithium sulfide  FeCl 2 (This is a transition metal)  Iron (II) chloride (ferrous chloride)  FeCl 3 (This is a transition metal)  Iron (III) chloride (ferric chloride)

 PtO 2  Platinum (IV) oxide  CuBr  Copper (I) bromide (cuprous bromide)  Zn 3 N 2  Zinc (II) nitride (Zn is almost always +2)  Sn 3 P 2  Tin (II) phosphide (stannous phosphide)

 Ca(OH) 2  Calcium hydroxide  NaSCN  Sodium thiocyanate  Al 2 (CrO 4 ) 3  Aluminum chromate  Mg(NO 2 ) 2  Magnesium nitrite

 NH 4 Cl  Ammonium chloride  Au 2 (CO 3 ) 3  Gold (III) carbonate  Pb(CN) 4  Lead (IV) cyanide  FePO 4  Iron (III) phosphate

 Review Ionic Formula Writing  Notes on Polyatomic Ions  Naming  Notes on naming Covalent Compounds  Properties of covalent compounds  HW: Naming monatomic and polyatomic formulas

 Bonds that exist between two non-metals  Two anions!!  Both atoms want to gain electrons so they share electrons in bonds to complete their octet.

 These exist between two different anions.  Ex: Carbon monoxide, CO, C==O  Many different solid forms, not crystalline  Relatively low melting and boiling point.  Poor conductors in all states!  Do not dissolve in water very well.  Organic compounds are examples of molecular substances.

 Bonds between one non-metal element  Ex: C 60 Buckminsterfullerene Buckyballs  Diamond, Graphite, and Carbon nanotubes

 Different shapes in the solid form.  High melting and boiling points  Often hard and brittle  Non-conducting solids  Do not dissolve in water well

1. First element using full element name 2. Second element name as if it were an anion (-ide) 3. Use prefixes to denote # of atoms present for both of the elements - exception: mono is NOT used for the first element. Ex: CO  Carbon monoxide Mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca

 One  mono-  Two  di-  Three  tri-  Four  tetra-  Five  penta-  Six  hexa-  Seven  hepta-  Eight  octa-  Nine  nona-  Ten  deca-

N2O3N2O3  dinitrogen trioxide N2O5N2O5  Dinitrogen pentoxide  Xenon tetrafluoride  XeF 4  Oxygen dichloride  OCl 2  Diphosphorus trioxide P2O3P2O3

 Review all types of naming  Notes on metallic substances  Practice Practice Practice  HW: Naming covalent compounds

1. S 2 F 3 4. PbO 2 2. BeS5. LiOH 3. CO 2 6. NCl 3

 Metallic bonds are described as a cluster of positive metal ions surrounded by a sea of their shared valence electrons.  Metallic Bonding is the type of bonding found in metallic substances.  The positive ions remain fixed in a crystal lattice, while the loosely-held valence electrons move freely throughout the entire crystal.  Melting/boiling points between covalent and ionic compounds.  Not soluble in water.

Insert figure 8.9 A Model of Metallic Bonding The positive metal ions are surrounded by a huge cloud of free flowing electrons.

 Metals are great conductors of electricity. Why?  Electricity can be described as a movement of charged particles, so if you have mobile charged particles present then electricity can flow.  For metals, the sea of electrons is basically a cloud of mobile charged particles.

 Malleable: Can be beaten into a thin sheet  Ductile: Can be pulled into a wire.  Why?  If you add stress you force like charges closer together. They repel each other and move apart, but instead of shattering, the particles rearrange with the sea of electrons.

 Metals are shiny!!  Why?  The valence electrons move within the “sea” around the positive ions of the metals.  When the light wave hits the electrons in the “sea”, the light “bounces” off of them or is reflected back by the electrons.  When this light hits our eyes, the appearance we see is that the metal is shiny.