I. Introduction to Bonding

A. Vocabulary (Talkin the talk)Chemical Bondattractive force between atoms or ions that binds them together as a unitbonds form in order todecrease potential energy (PE)increase stability2A. VocabularyCHEMICAL FORMULAMolecularFormula FormulaUnitIONICCOVALENTCO2NaCl(True molecules) 3Ionic Bonding - Crystal Lattice

B. Ionic and Covalent traits

6B. Basics of Ionic and Covalent BondsNaCl+-IONIC

Electrons are: Transferred!5B. Ionic and Covalent traitsClClCOVALENT

Electrons are: Shared!7Covalent Bonding - True Molecules

B. Ionic and Covalent traitsDiatomic Molecule

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B. Ionic and Covalent traits

C. Bond PolarityElectronegativity Trend (p. 151)Increases up and to the right.

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C. Bond PolarityElectronegativityAttraction an atom has for electrons.In covalent molecules:higher e-neg atom -lower e-neg atom +11C. Bond PolarityMost bonds are a blend of ionic and covalent characteristics.Difference in electronegativity determines bond type.3.31.70.30.0Difference in electronegativity100%50%5%0%% Ionic CharacterNon polarCovalentPolarCovalentIonic12Chapter 6: Bonding Chemical Bonding Describe covalent, ionic and metallic bonds Classify bond type by electronegative difference Explain why atoms form bonds Draw Lewis structures Classify covalent and ionic compounds by physical properties Predict molecular geometry using VSEPR theory1E. Lewis StructuresElementValence e-BondsOctet RuleHydrogenGroup 2Group 3 (B)CarbonNitrogenOxygenHalogens123 For covalent bonds1234567432124 (rare)6 (boron)888823Nonpolar

Polar

Ionic

View Bonding Animations.C. Bond Polarity

15A. VocabularyION charged atom orgroup of atomsPositiveChargeNegativeChargeSO4-2Cl-Mg+2NH4+CATIONANION4

balanced attraction & repulsionincreased repulsionattraction vs. repulsionD. Bond FormationPotential Energy Diagram!17

no interactionattraction vs. repulsionincreased attractionD. Bond FormationPotential Energy Diagram!18

Bond EnergyD. Bond FormationBond LengthBond EnergyEnergy required to break a bond!19E. Lewis StructuresElectron Dot Diagramsshow valence e- as dotsdistribute dots like arrows in an orbital diagram*4 sides = 1 s-orbital, 3 p-orbitals*XNa Mg Al C N O F Ne20E. Lewis StructuresOctet RuleMost atoms form bonds in order to obtain 8 valence e-Full energy level stability ~ Noble GasesNe21E. Lewis Structures

StructuralFormulaLewis StructureH C C HH HH HWhats the difference?22E. Lewis StructuresExamples

NaClNaCl+1-1Covalent show sharing of e-Ionic show transfer of e-24E. Lewis StructuresCaClClCaClCl-1-1+225E. Lewis StructuresNonpolar Covalent - no charges

Polar Covalent - partial chargesFFFFHOHHOH-+26E. Lewis StructuresIsomers Same formula different structure.

C3H7OH

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IONICCOVALENTBond FormationType of StructureSolubility in WaterElectrical ConductivityOtherPropertiese- are transferred from metal to nonmetalhighyes (solution or liquid)yese- are shared between two nonmetalslownousually notMeltingPointcrystal latticetrue moleculesF. Ionic and Covalent traitsPhysical Statesolidliquid or gas mostlyodorous, Make true moleculesMake formula units28G. VSEPR TheoryValence Shell Electron Pair Repulsion TheoryElectron pairs orient themselves in order to minimize repulsive forces.

29G. VSEPR TheoryTypes of e- PairsBonding pairs - form bondsLone pairs - nonbonding e-Lone pairs repel more strongly than bonding pairs!!!30F. VSEPR Theory Use a chart todetermine shape

31H. Common Shapes2 Bonded to central atom0 lone pairsLINEARBeHHBeH2

323 Bonded to central atom0 lone pairsTRIGONAL PLANARH. Common ShapesBFFF

BF3334 bonds to central atom0 lone pairTETRAHEDRALH. Common Shapes

CHHHHCH4343 bonded to central atom1 lone pairTRIGONAL PYRAMIDALNH3H. Common Shapes

NHHH352 bonded to central atom2 loneBENTH2OH. Common Shapes

OHH36Metallic Bonding - Electron SeaI. Metallic Bonds

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electron seaMETALLICBond FormationType of StructureSolubility in WaterElectrical ConductivityOtherPropertiesMeltingPointI. Metallic Bonds (on pg 5)Physical Statee- are delocalized among metal atomsvery highyes (any form)nomalleable, ductile, lustroussolid38I. Metallic Bonding Malleability- Hammer into sheets Ductility- Draw into thin wire39J. Intermolecular Forces...that's all well and good, but what holds different molecules together?

When H2O is in its solid state, what is holding it like that?

When CO2 is in its solid state, what is holding it like that?40J. Intermolecular ForcesDipoles - polar covalent molecules where there is an asymmetrical electron density across the entire molecule (not just in the bonds)Dipole-dipole interaction occur when dipoles line up and attract each otherConsider H2O, NH3, CH4, and CO2, given the shape of the molecule, will one end have a different charge than the other?

41J. Intermolecular Forces

42K. Hydrogen bondsHydrogen bonds - super dipole-dipole interactions between + on hydrogen and - charges on other parts of a molecule

43K. Hydrogen bonds - Ice

44L. London Dispersion forcesWhat about non-polar molecules and atoms, like the noble gases? How do they form things like liquid helium and solid oxygen without dipole interactions?London dispersion forces are the attractive forces between temporary dipoles created by random motion of electronsThe more e- involved, the stronger the London dispersion forces

45L. London Dispersion forces of Helium

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