1. What happens if interacting things do not want to give? They must share…

2. What does it mean to share an e- ? –shared e- “belongs” to both atoms –both complete octets –valence energy levels of overlap the sharing/overlap binds the atoms together and is called a covalent bond Linked Pg 309-311

3. Ionic vs. Covalent Bond Metals give e-; Nonmetals take e-; electrostatic attraction created keeps atoms together –Ions “stick” together = formula unit Nonmetals share e- forming overlapping valences that keep atoms together –Overlap forms a new shape=molecule Write in the box How are these diagrams different?

4. Drawing Bonding Venn diagram model Draw Lewis symbol for Cl Is one Cl noble gas stable? Lewis Structure show shared pair(s) as line and unshared pairs as dots single line = “single bond” Pg 309-311

5. Draw Lewis symbols for each atom of water then match up the electrons to make bonds! Draw its Lewis structure overlap creates a new molecule with its own shape What about water??? Pg 309-311 Venn diagram

6. Try N bonding with H Draw Lewis structure for new molecule. Pg 309-311 Draw Lewis symbol for N & H How will they share electron pairs???

7. Try matching up carbon with hydrogen…

8. Drawing Lewis Structures “step by step” example…PCl 3 1.Sum valence electrons for all atoms 2.Divide total # of ve - by 2 to give # of electron pairs 3.Determine which atom is the CENTRAL atom??? 4.Surround the central atom with 4 electron pairs 5.Put the other atoms around the central atom 6.Use the remaining pairs to complete octets around each remaining atom 7.If there are not enough electron pairs to provide an octet for each atom, move nonbonding electron pairs between 2 atoms that already share a pair Pg 317-319

9. PCl 3 is used to make numerous phosphate compounds for industrial purposes  one of which is PSCl 3  which is then used to make parathion which is used as an insecticide

10. Lewis Structure Practice Cl 2 NF 3 HF CHCl 3 (C is central) Ions have a charge. How will this change your total # of valence electrons??? sulfate ion chlorate ion

11. Multiple Bonds sigma (σ) bond - covalent bond in which electron density is concentrated along the internuclear axis pi (π) bond - results from the overlap between two p orbitals oriented perpendicularly to the internuclear axis

12. Equivalent Resonance Structures Draw Lewis Structure for: SO 3 Pg 322-325

13. Equivalent Resonance Structures Draw Lewis Structure for: CO 3 -2

14. Non-Equivalent Resonance Structures What if you can draw two completely different Lewis Structures each following the octet rule, which one is most reasonable??? Draw 2 different Lewis structures for: CO 2 “carbon dioxide”

15. Formal Charge charge difference between valence electrons of each isolated atom and number of electrons assigned to atom in a specific Lewis Structure The best structure has (1) the fewest formal charges and (2) the negative charge on the most electronegativity atom Pg 320-321

16. VESPR Valence Electron Shell-Pair Repulsion Electron domain – region about a central atom in which electrons are likely to be found ((bonding AND nonbonding)) Bonding electrons – electrons shared between atoms Nonbonding electrons (lone pairs) – electrons that are not shared but are needed to complete atoms octet Pg 346-357

17. VESPR Electron domains (lone pairs and bonds) will orient naturally to “try to get out of each other’s way” The best arrangement of a given number of electron domains is the one that minimizes the repulsion among them 3-d shape depends on the bond angles resulting from domain arrangement Pg 346-357 Linked

18. 1) draw each Lewis structure 2) determine the # of electron domains around the CENTRAL ATOM 3) how many electron domains are bonding sites? H2OCH4 NH3

23. Hybrids A hybrid results from combing two of the same types of things giving characteristics of both Hybridization explains bond angles and resulting geometries shape of a hybrid orbital is different from original total number of atomic orbitals remains constant

24. sp hybridization (example BeF 2 ) Be no single electrons F 1 single electron if Be “promotes” an electron Then 2 single electrons are available. BUT one s and one p would give not give the predicted symmetrical linear geometry.

25. sp hybridization (example BeF 2 ) SO valence-bond theory says they “mix” to create 2 new AND identical sp orbitals creating symmetrical geometry Be now has 2 identical/symmetrical sp orbitals that can overlab with F’s 2p orbitals Link

26. sp 2 hybridization

27. sp 3 hybridization Link

28. sp 3 d & sp 3 d 2 hybridization

29. When sharing, why would one interacting thing get more than another???

30. Electronegativity - ability of an atom in a molecule to attract electrons to itself (electron affinity) Pg 312-317 Linked

31. Polarity Pg 312-317 Linked Polar (“puller”) – atoms pull electrons differently; results in uneven distribution –Gives bond partial positive and partial negative “dipoles” Nonpolar – atoms pull electrons equally; results in even distribution

32. How “puller” is polar? use electronegativity values to determine the extent of the polarity to be “puller” difference MUST be greater than 0.4 Pg 312-317 non-puller polar bear puller polar bear Example: Determine extent of polarity of a B – Cl bond

33. Dipole Moments Which of the following bonds is the most polar? Which one is Non-polar? Cl – ClH – O C – OBr – F N – H C – H

34. Molecular Polarity Dipole moment of multi-atom molecules depends on BOTH polarities of individual bonds and molecular geometry Pg 263-266

35. Molecular Polarity pola r non- polar

36. Polarity results in …. Intermolecular Attraction Dipole-Dipole - of one molecule attracts to the of another Pg 445-446

37. Hydrogen bonding dipole-dipole attraction of H in a polar bond to an F, O, or N in another molecule H bonding is stronger than regular dipole-dipole due to an unshared electron pair Linked Pg 449-451

38. Hydrogen bonding of water Pg 449-451

39. Ion – Dipole attraction Attraction of ionic charge and partial dipole charge of a polar molecule Pg 445-446

40. How do compounds dissolve??? Linked ion–dipole attraction separates NaCl formula units into isolated ions dipole-dipole attraction cause water molecules to surround and isolate sugar molecules

41. Naming Binary Molecular Compounds element furthest to the left on table should be written first if same group element with higher atomic # should be written first second element name should end with “ide” Greek prefixes designate # of atoms of each element ((prefix mono is NOT used for first element))) Pg 66-67

42. Prefixes 1 mono2 di3 tri 4 tetra5 penta6 hexa 7 hepta8 octa9 nona 10 deca SO… CO SF 6 N 2 O P 2 O 3 Pg 66-67

43. Practice Cl 2 O 3 BrF 3 I 2 O 4 SO 3 dihydrogen monosulfide Iodine monobromide Nitrogen monoxide Chlorine dioxide