Introduction to Chemical BondingIntroduction to Chemical Bonding

Table of ContentsLecture/Lab/Activity Date Pg#

22. The Periodic Table 9/24/10 4723. Periodic Def & Trends 9/27/10 4924. Electron config practice 10/4/10 5125. Ions and Oxidation Numbers 10/5/10 5326. Lewis Dot Diagram 10/6/10 5427. Intro to Chemical Bonding 10/7/10 57

Objective:The student will record lecture notes on the Introduction to Chemical Bonding to make a comparison of the different types of Chemical bonds & bond polarity.

Agenda:Introduction to Chemical Bonding – Lecture

VocabularyVocabulary

Chemical Bondattractive force between atoms

or ions that binds them together as a unit

bonds form in order to…decrease potential energy (PE)

increase stability

Chemical Bondattractive force between atoms

or ions that binds them together as a unit

bonds form in order to…decrease potential energy (PE)

increase stability

VocabularyVocabulary

CHEMICAL FORMULA

MolecularFormula

FormulaUnit

IONIC COVALENT

COCO22NaClNaCl

VocabularyVocabulary

COMPOUND

TernaryCompound

BinaryCompound

2 elementsmore than 2

elements

NaNONaNO33NaClNaCl

VocabularyVocabulary

ION

PolyatomicIon

MonatomicIon

1 atom 2 or more atoms

NONO33--NaNa++

Types of Chemical BondsTypes of Chemical BondsIONIC COVALENT

Bond Formation

Type of Structure

Solubility in Water

OtherProperties

high

yes (solution or liquid)

yes

low

no

usually not

MeltingPoint

Physical State

solid liquid or gas

odorous

Electrical Conductivity

crystal lattice

e- are transferred from metal to nonmetal

true molecules

e- are shared between two nonmetals

Types of Chemical BondsTypes of Chemical BondsMETALLIC

Bond Formation

Type of Structure

Solubility in Water

Electrical Conductivity

OtherProperties

MeltingPoint

Physical State

e- are delocalized among metal atoms

very high

yes (any form)

no

malleable, ductile, lustrous

solid

“electron sea”

Bond PolarityBond Polarity

Most bonds are a blend of ionic and covalent characteristics.

Difference in electronegativity determines bond type.

Most bonds are a blend of ionic and covalent characteristics.

Difference in electronegativity determines bond type.

Bond PolarityBond PolarityElectronegativity

Attraction an atom has for a shared pair of electrons.

higher e-neg atom -

lower e-neg atom +

ElectronegativityAttraction an atom has for a shared

pair of electrons.higher e-neg atom -

lower e-neg atom +

Bond PolarityBond PolarityElectronegativity Trend

Increases up and to the right.

Electronegativity Trend Increases up and to the right.

Nonpolar Covalent Bonde- are shared equallysymmetrical e- densityusually identical atoms

Nonpolar Covalent Bonde- are shared equallysymmetrical e- densityusually identical atoms

Bond PolarityBond Polarity

+ -

Bond PolarityBond PolarityPolar Covalent Bond

e- are shared unequallyasymmetrical e- densityresults in partial charges (dipole)

Polar Covalent Bonde- are shared unequallyasymmetrical e- densityresults in partial charges (dipole)

Nonpolar

Polar

Ionic

View Bonding Animations.

Bond PolarityBond Polarity

Bond PolarityBond Polarity

Examples:

Cl2

HCl

NaCl

Examples:

Cl2

HCl

NaCl

3.0-3.0=0.0Nonpolar

3.0-2.1=0.9Polar

3.0-0.9=2.1Ionic

Least electronegative element = Cs – 0.7

Most electronegative element = F – 4.0

Ionic = EN > 1.7Polar-covalent = EN 0.3 > 1.7Nonpolar-covalent = EN < 0.3

Least electronegative element = Cs – 0.7

Most electronegative element = F – 4.0

Ionic = EN > 1.7Polar-covalent = EN 0.3 > 1.7Nonpolar-covalent = EN < 0.3

Bond PolarityBond Polarity