I II III IV

Ch. 6 & 7 - Chemical Bonding

I. Introduction toBonding

(p. 161 – 163)

A. Vocabulary

Chemical Bond

attractive force between atoms or ions that binds them together as a unit

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

A. Vocabulary

CHEMICAL FORMULA

MolecularFormula

FormulaUnit

IONIC COVALENT

COCO22NaClNaCl

A. Vocabulary

COMPOUND

TernaryCompound

BinaryCompound

2 elementsmore than 2

elements

NaNONaNO33NaClNaCl

A. Vocabulary

ION

PolyatomicIon

MonatomicIon

1 atom 2 or more atoms

NONO33--NaNa++

IONIC COVALENTBond Formation

Type of Structure

Solubility in Water

Electrical Conductivity

OtherProperties

e- are transferred from metal to nonmetal

high

yes (solution or liquid)

yes

e- are shared between two nonmetals

low

no

usually not

MeltingPoint

crystal lattice true molecules

B. Types of Bonds

Physical State solid liquid or gas

odorous

“electron sea”

METALLICBond Formation

Type of Structure

Solubility in Water

Electrical Conductivity

OtherProperties

MeltingPoint

B. Types of Bonds

Physical State

e- are delocalized among metal atoms

very high

yes (any form)

no

malleable, ductile, lustrous

solid

C. Bond Polarity

Most bonds are a blend of ionic and covalent characteristics

Difference in electronegativity determines bond type

C. Bond Polarity

Electronegativity – Remember this? Attraction an atom has for a shared pair

of electrons. higher e-neg atom -

lower e-neg atom +

C. Bond Polarity

Electronegativity Trend (p. 151) Increases up and to the right.

Nonpolar Covalent Bond e- are shared equally symmetrical e- density usually identical atoms

C. Bond Polarity

+ -

C. Bond Polarity

Polar Covalent Bond e- are shared unequally asymmetrical e- density results in partial charges (dipole)

Nonpolar

Polar

Ionic

View Bonding Animations.

C. Bond Polarity

C. Bond Polarity

Examples:

Cl2

HCl

NaCl

3.0-3.0=0.0Nonpolar

3.0-2.1=0.9Polar

3.0-0.9=2.1Ionic