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
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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 -
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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.
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C. POLYATOMIC IONS ClO 4 - 1 Cl 7e - = 7e - 4 O 6e - = 24e -
31e - O O Cl O O + 1e - 32e - - 8e - 24e -
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C. POLYATOMIC IONS NH 4 + 1 N 5e - = 5e - 4 H 1e - = 4e - 9e -
H H N H H - 1e - 8e - - 8e - 0e -
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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.
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D. RESONANCE STRUCTURES O O S O O O S O O O S O n SO 3
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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!!!
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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
