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What happens if interacting things do not want to give?

What happens if interacting things do not want to give?. They must share…. What does it mean to share an e- ?. Linked. 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.

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What happens if interacting things do not want to give?

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

  2. What does it mean to share an e- ? Linked • 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. Write in the box How are these diagrams different? 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

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

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

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

  7. Try matching up carbon with hydrogen…

  8. Pg 317-319 Drawing Lewis Structures “step by step” example…PCl3 • Sum valence electrons for all atoms • Divide total # of ve- by 2 to give # of electron pairs • Determine which atom is the CENTRAL atom??? • Surround the central atom with 4 electron pairs • Put the other atoms around the central atom • Use the remaining pairs to complete octets around each remaining atom • 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

  9. PCl3 is used to make numerous phosphate compounds for industrial purposes one of which is PSCl3  which is then used to make parathion which is used as an insecticide

  10. Lewis Structure Practice Cl2 NF3 HF CHCl3 (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: SO3 Pg 322-325

  13. Equivalent Resonance Structures Draw Lewis Structure for: CO3-2

  14. Non-Equivalent Resonance StructuresWhat 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: CO2 “carbon dioxide”

  15. Pg 320-321 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

  16. VESPRValence Electron Shell-Pair Repulsion Pg 346-357 • 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

  17. VESPR Pg 346-357 • 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 Linked

  18. 1) draw each Lewis structure 2) determine the # of electron domains around the CENTRAL ATOM3) how many electron domains are bonding sites? H2O CH4 NH3

  19. 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

  20. sp hybridization (example BeF2) 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.

  21. sp hybridization (example BeF2) 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

  22. sp2 hybridization

  23. sp3 hybridization Link

  24. sp3d & sp3d2 hybridization

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

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

  27. Pg 312-317 Linked Polarity • 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

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

  29. Dipole Moments • Which of the following bonds is the most polar? Which one is Non-polar? Cl – Cl H – O C – O Br – F N – H C – H

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

  31. Molecular Polarity polar polar non-polar non-polar polar

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

  33. 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

  34. Hydrogen bonding of water Pg 449-451

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

  36. 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

  37. Naming Binary Molecular Compounds Pg 66-67 • 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)))

  38. Pg 66-67 Prefixes 1 mono 2 di 3 tri 4 tetra 5 penta 6 hexa 7 hepta 8 octa 9 nona 10 deca SO… CO SF6 N2O P2O3

  39. Practice • Cl2O3 BrF3 • I2O4 SO3 • dihydrogen monosulfide • Iodine monobromide • Nitrogen monoxide • Chlorine dioxide

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