Lewis Dot Structure

Predicts Molecular Structure (Shape) Looks at Central Atom of the Compound # Electron pairs,

Bonded Non-Bonded

Electrons Repel Each Other Maximize distance between each other

BeF2

Be

Be

F

F

FLet’s Try to make the atom stable by using

the Octet Rule – Outer Level 2 or 8

BeF

F

Why Is the Compound Linear in Shape?

2 Electrons in the outer

shell

7 Electrons in the outer shell

FBeFTwo bonded pairs don’t like each other (repel)

BCl3

B

B

Cl

ClLet’s Try to make the atom stable by using

the Octet Rule – Outer Level 2 or 8

3 Electrons in the outer

shell

7 Electrons in the outer shell

Cl Cl

B ClCl

Cl

B Cl

Cl

ClWhat is the Shape?

3 shared pairs of electrons

Triangle Shape – Trigonal PlanarB Cl

Cl

Cl

Triangle has three vertexes

CH4

C H

CLet’s Try to make the atom stable by using

the Octet Rule – Outer Level 2 or 8

4 Electrons in the outer

shell

1 Electrons in the outer shell

H H H H

C HH

HH

What is the Shape?

4 shared pairs of electrons

3-D 4 sided figure - Tetrahedral

Square has four corners

C HH

HH

CH

HHH

H2OH

H

O

HLet’s Try to make the atom stable by using

the Octet Rule – Outer Level 2 or 8

O

1 Electrons in the outer

shell6 Electrons in the outer shell

OHH

4 pair of electrons

OHH

What is the Molecules Shape?

Special TetrahedralBent

OHH

Tetrahedral

Rule:Opposites attractLikes repel

2 shared electron pairs2 Unshared Electron Pairs

3 pair of shared 1 pair of unshared

NHH H

Trigonal-Pyramidal

SF2

PCl3

SO2

Linear

Trigonal-Pyramidal

Bent

Trigonal-Planar

Tetrahedal

http://wps.prenhall.com/esm_brown_chemistry_9/2/667/170888.cw/index.html

More Review http://www.mhhe.com/physsci/

chemistry/chang7/esp/folder_structure/bo/m3/s3/index.htm