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
Slide 3
COMPOUND Ternary Compound Binary Compound 2 elements more than
2 elements NaNO 3 NaCl
Slide 4
ION Polyatomic Ion Monatomic Ion 1 atom 2 or more atoms NO 3 -
Na +
Slide 5
IONIC COVALENT Bond Formation Type of Structure Solubility in
Water Electrical Conductivity Other Properties e - are transferred
from metal to nonmetal high yes (solution or liquid) yes e - are
shared between two nonmetals low no usually not Melting Point
crystal lattice true molecules TYPES OF BONDS Physical State solid
liquid or gas odorous
Slide 6
electron sea METALLIC Bond Formation Type of Structure
Solubility in Water Electrical Conductivity Other Properties
Melting Point TYPES OF BONDS Physical State e - are delocalized
among metal atoms very high yes (any form) no malleable, ductile,
lustrous solid
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
Slide 19
I LEWIS DIAGRAMS Molecular Structure
Slide 20
RULE Remember Most atoms form bonds in order to have 8 valence
electrons.
Slide 21
Hydrogen 2 valence e - Groups 1,2,3 get 2,4,6 valence e -
Expanded octet more than 8 valence e - (e.g. S, P, Xe) Radicals odd
# of valence e - A. OCTET RULE Exceptions: F B F F H O H N O Very
unstable!! F F S F F
Slide 22
B. DRAWING LEWIS DIAGRAMS Find total # of valence e -. Arrange
atoms - singular atom is usually in the middle. Form bonds between
atoms (2 e - ). Distribute remaining e - to give each atom an octet
(recall exceptions). If there arent enough e - to go around, form
double or triple bonds.
Slide 23
B. DRAWING LEWIS DIAGRAMS CF 4 1 C 4e - = 4e - 4 F 7e - = 28e -
32e - F F C F F - 8e - 24e -
Slide 24
B. DRAWING LEWIS DIAGRAMS BeCl 2 1 Be 2e - = 2e - 2 Cl 7e - =
14e - 16e - Cl Be Cl - 4e - 12e -
Slide 25
B. DRAWING LEWIS DIAGRAMS CO 2 1 C 4e - = 4e - 2 O 6e - = 12e -
16e - O C O - 4e - 12e -
Slide 26
C. POLYATOMIC IONS To find total # of valence e - : Add 1e -
for each negative charge. Subtract 1e - for each positive charge.
Place brackets around the ion and label the charge.
Slide 27
C. POLYATOMIC IONS ClO 4 - 1 Cl 7e - = 7e - 4 O 6e - = 24e -
31e - O O Cl O O + 1e - 32e - - 8e - 24e -
Slide 28
C. POLYATOMIC IONS NH 4 + 1 N 5e - = 5e - 4 H 1e - = 4e - 9e -
H H N H H - 1e - 8e - - 8e - 0e -
Slide 29
C. POLYATOMIC IONS OH - 1 O 6e - = 6e - 1 H 1e - = 1e - 7e - O
H + 1e - 8e - - 8e - 0e -
Slide 30
D. RESONANCE STRUCTURES Molecules that cant be correctly
represented by a single Lewis diagram. Actual structure is an
average of all the possibilities. Show possible structures
separated by a double-headed arrow.
Slide 31
D. RESONANCE STRUCTURES O O S O O O S O O O S O n SO 3
Slide 32
I MOLECULAR GEOMETRY
Slide 33
VSEPR THEORY Valence Shell Electron Pair Repulsion Theory
Electron pairs orient themselves in order to minimize repulsive
forces.
Slide 34
VSEPR THEORY Types of e - Pairs Bonding pairs - form bonds Lone
pairs - nonbonding e - Lone pairs repel more strongly than bonding
pairs!!!
Slide 35
VSEPR THEORY Lone pairs reduce the bond angle between atoms.
Bond Angle
Slide 36
DETERMINING MOLECULAR SHAPE Draw the Lewis Diagram. Tally up e
- pairs on central atom. double/triple bonds = ONE pair Shape is
determined by the # of bonding pairs and lone pairs. Know the 8
common shapes & their bond angles!
Slide 37
COMMON MOLECULAR SHAPES 2 total 2 bond 0 lone LINEAR 180 BeH
2
Slide 38
COMMON MOLECULAR SHAPES 3 total 3 bond 0 lone TRIGONAL PLANAR
120 BF 3
Slide 39
COMMON MOLECULAR SHAPES 3 total 2 bond 1 lone BENT